The Macworld Expo, formerly the most anticipated Apple event of the year (before Apple kicked out its legs by pulling Steve Jobs and announcing it was pulling out entirely next year), starts on Monday. Not surprisingly, rumors of what we can expect from Apple at the event are all over the map. Apple’s senior vice president of product marketing, Phil Schiller, will be giving the keynote address in place of Jobs and he certainly will have some things to announce, but what?

The rumors:

New Mac minis –It’s been a long time since Apple last refreshed its small desktop computer in any way (2007). It’s been even longer since it underwent a redesign — in fact, it never really has since its launch in 2005, unless you consider a transition to Intel chips a redesign. While images of a new, slimmer Mac mini floating around the web probably aren’t real, an updated system with an updated look seems pretty likely. Wired heard about a Macworld launch of the new Mac mini a few weeks ago, and Apple is transitioning all its products to the newer NVIDIA chips it now uses in its MacBook line. That makes this rumor very likely true.

New iMacs — While it’s only been several months since the iMac line was last refreshed, that’s a more normal timeline for Apple to update a product (rather than the Mac mini’s several-year timeline). New Intel chips as well as new NVIDIA chips suggest the iMac is due for an update. Some rumors have it getting quad-core chips meant for actual desktops (the iMac right now uses the same mobile chips that the MacBooks do) and needing a new cooling system because of it, but new quad-core mobile chips from Intel exist also. Again, this rumor seems very likely true.

Steve Jobs is sick — As soon as it was announced that Jobs is not doing the keynote at MacWorld, the rumors about his health starting flying. But CNBC, the only outlet with an actual source at the time, said the decision was a political one and had nothing to do with Jobs’ health. But today, Gizmodo quoted a source it trusts as saying that Jobs’ health is in decline, and that is the reason for his Macworld pull out. People are already panicking, and the company’s stock is sliding.

But once again, CNBC’s Jim Goldman refutes this with his own source saying that Jobs is “(still) fine.” He goes on to slam Gizmodo with the closing line, “Meantime, unsourced garbage nuking its shares is just that.” Sadly, this will not end until we see Jobs in public again. Apple 2.0’s Philip Elmer-DeWitt thinks Jobs may make a surprise appearance during the Macwold keynote to defy his skeptics. I agree. This rumor is iffy at best, and irresponsible at worst.

iPhone nano — If case makers dictated Apple’s upcoming products, this rumors would be 100 percent true. For a couple of weeks now, one iPhone case maker has listed a new “iPhone nano” case on its website, and now a second one is getting in on the act. Both suggest a product that is shorter than the current iPhone, with a smaller screen. But is it real? The rumor has actually been around for a long time, but some argue that a smaller-form iPhone makes no sense because it would be harder to use. But if it’s smaller and cheaper (as in $99), I think we may just see one at some point in 2009. But that probably isn’t a lock for MacWorld, so I’ll say this is somewhat likely true.

32GB iPhone — In the early months of last year, Apple unveiled a new 16 gigabyte iPhone (before the iPhone 3G launched). Could it do the same this year? It certainly could. After all, there’s already a 32GB iPod touch. Perhaps Apple will unveil a 32GB iPhone and a 64GB iPod touch at the current high-end price points while dropping the 8GB iPhone 3G model. Maybe that’s why we’re seeing $99 refurbished iPhones from AT&T. This certainly would make a lot of people happy and seems somewhat likely true.

Apple netbook — This rumor is likely caused by one thing: The poor economy. Because times are tough, analysts are expecting Apple to come out with a cheap laptop for the masses. But that logic is faulty, and Jobs himself has said that Apple doesn’t “know how to make a $500 computer that’s not a piece of junk, and our DNA will not let us ship that.” Eventually, I bet we’ll see a small form-factor computer from Apple that goes in between the iPhone and the MacBook Air, but I would guess that it’ll be the mythical touch tablet, and not a netbook. This rumor is not likely true.

iTunes goes DRM-free — Several reports have Apple in negotiations to bring all of the major labels on board with giving their music DRM-free to its iTunes store. I fully expect this to happen at some point next year, but the question here is about timing. Could Apple announce a fully DRM-free iTunes at Macworld? Maybe. After all, there have been some pretty weird things happening in the iTunes Plus (the name for DRM-free music in iTunes) area of the store recently. Some previously DRM-laced tracks are showing up without DRM, and the section disappeared entirely for a while. This rumor is somewhat likely true.

Snow Leopard — While Apple will almost surely be showing off its new operating system (also known as OS X 10.6), one of the hot rumors that was circulating several weeks ago was that it may be ready to ship soon. The beta builds going around don’t seem to suggest that, but who knows. After all, Snow Leopard isn’t an OS focused on reinventing the wheel, but instead is about tweaking that wheel to get the best possible performance and will apparently make use of Apple’s new NVIDIA GPUs — which the entire Apple product line may have very soon (see above) — to improve performance. This rumor is not likely true, but somewhat plausible.

Apple home server — This rumor from just yesterday comes from 9 to 5 Mac, which claims Apple has plans to turn its Time Capsule wireless hard drive device into a home media server of sorts to compete with a similar product from HP. This device would allow users to access their media files from anywhere in the world over the Internet using a special web address that’s tied into a MobileMe account. Sounds awesome, and I want this, but is it likely at Macworld? Probably not.

Update: New 17-inch MacBook Pros — These appear to be a lock at this point, but the real surprise is that they apparently won’t have a removable battery. Instead, Apple will use a longer-lasting battery which may or may not be based on Silver-Zinc technology. The new laptops are very likely, while the possible new battery technology seems fairly likely given what we know about startups like ZPower which work in Silver-Zinc technology.

Update: Red iPhones — I’m calling this picture bogus. If Apple launches red iPhones, it’ll be for Product Red. That could happen, but is probably unlikely.

Wildcards — It’s possible that Apple will use its last Macworld to pull something out of its sleeve that the rumor mill hasn’t heard about. Maybe a new Apple TV? One with a Blu-ray player built-in would be great but seems to be against the direction Apple is heading with its iTunes distribution. So perhaps one with more storage space — 500GB or 1TB? After all, I’ve only had mine about a month and I’m already more than halfway through my 160GB of space.

What about a new Mighty Mouse? You know, like perhaps the one that patents have hinted at and that mock-ups have been made for that includes multi-touch capabilities? That would be a nice little surprise.

Overall — There are still several days until Macworld, and I’m sure we’ll hear more rumors between now and then, but as it stands right now, I’d bet on new Mac minis and revamped iMacs being unveiled at the show. While both product updates would be nice, if those are the only two things we see, it’ll be a pretty lackluster keynote and would basically leave Schiller hanging out to dry (again, leading his first keynote).

So I’d bet there’ll also be at least one more announcement, probably related to the iPhone. The iPhone nano would definitely make waves, but the 32GB iPhone seems a more likely move. Unless the two are tied to each other — as in, the iPhone nano is the new 8GB iPhone, while the “proper” iPhones are available at 16GB and 32GB.

VentureBeat will be at Macworld next week, including the keynote on Tuesday. Check back here for live coverage.