One thing announced at today’s Macworld event in San Francisco that is sure to cause a lot of discussion is the new 17-inch MacBook’s eight-hour battery. That discussion will undoubtedly be both positive and negative as there will be two camps: Those who will hate that the battery is no longer replaceable, and those who will drool over the new battery’s supposed eight-hour lifespan. Count me in the latter category.

While I understand the arguments that were being made by several people when this new battery was still only a rumor — the biggest of which seems to be wanting to replace the battery on long flights or other extended trips — at eight hours, it seems to me that will rarely be the case. As former Apple employee turned blogger Chuq Von Rospach noted the other day:

I’d be amazed if 10% of Apple Laptop owners own a second battery. I’d be amazed if half the users who own second batteries use both batteries more than occasionally.

It does seem to be an edge case more than a regular requirement that users need or want to change the battery — and that was before eight hours was promised. Even better, Apple is now saying these new batteries can be recharged 1,000 times before they start losing some of their charge. Standard batteries typically last 200 to 300 charges.

My only problem with this battery is that it’s only in the 17-inch MacBook. When this comes to the other MacBooks — which you can be sure it will — I’ll snap one up in an instant. I wonder how much battery life they can squeeze out of the 13-inch MacBook? It’s a much smaller screen, so perhaps it’s not unreasonable to think they can get to 10 hours of battery life (though the battery will be smaller). That would be incredible.

Truth is, eight hours is already incredible. We still need to see the third-party tests to confirm it can actually hit eight hours, but if it’s anywhere near there, this is a big step forward in laptop battery technology. I’ll take those extra hours of charge with a laptop that’s thinner than its previous iteration over a removable battery anyday.

See more discussion about this topic that went on live in our FriendFeed room earlier today.