Here’s our roundup of the week’s tech business news. First, the most popular stories VentureBeat published in the last seven days:

nanowire skinResearchers make artificial skin from nanowires so a robot can unload your dishwasher — The rise of the machines has begun. Researchers have created artificial skin from electronic materials known as semiconductor nanowires.

The secret of Groupon’s success is … good writing? — Among startups, there’s a tendency to emphasize product technology, rather than fuzzier skills and qualities that don’t “scale”. But chief executive Andrew Mason said that the success of his popular social buying site Groupon had less to do with brilliant tech and more with good writing, and with unfashionable technology like email.

Nasty surprise for some Xbox 360 owners: No Halo Reach co-op for you — Gamers who thought they were making a smart move by picking up Microsoft’s entry-level Xbox 360, which retails for $199 and comes with 4GB of memory, faced a nasty dose of reality when they found themselves unable to access Halo: Reach’s online co-op mode.

Halo: Reach generates $200M in sales in first 24 hours — Halo: Reach became the biggest game of the year in just 24 hours.

Yahoo unveils three-year plan to become cool again — Chief products officer Blake Irving acknowledged that the company has a challenge in “bringing cool back to Yahoo.”

And here are five more stories we think are important, thought-provoking, or fun:

dynamics card 20VentureBeat’s 5 favorite DEMO companies — VentureBeat’s writers chose the best launches among the 70 companies who took the stage at the DEMO conference.

Intel’s AppUp store puts chips down in Apple, Google rivalry — Intel isn’t happy just putting its chips into every imaginable device. It now wants to help developers sell apps that run on the devices its chip powers, too.

Sony PlayStation Move’s creator wants motion control to be as accurate as possible (video) — Richard Marks, co-creator of the PlayStation Move, likes to be right on target. Here he’s interviewed by VentureBeat’s Dean Takahashi.

Aurora’s rebranding bets on protein bars and lotion, not biofuel — Aurora Biofuels is no more. The company announced Monday it has changed its name to Aurora Algae, effectively repositioning itself in a crowded biofuels market by no longer tying its name or products to just biofuels.

Windows Phone 7 delayed for Verizon, Sprint, other CDMA networks until 2011 — In what will certainly be looked at as a blow for Microsoft, the company revealed that its upcoming Windows Phone 7 mobile operating system won’t support CDMA networks like Verizon and Sprint until the first half of 2011.