That's just battery life... wait until we see what the heat will be like! Seriously, even my Macbook Air gets hot under mild load -- the only reason I tolerate it is because it sits on a desk.

Fans and vents on a tablet... I just can't see that catching on for many people. The ARM model is more promising, but this competes much more closely with the iPad.

Also, the video was very funny with the pen input -- his palm interferes with the initial demo and 20 seconds later he's talking about their amazing palm rejection technology. Don't even get me started on the fact that none of the presenters seemed able to get the swipe-in-from-the-side gesture to work on the first try.

What it will offer though is a full compatibility to existing windows application. People might be ready to lose a few hours of battery life for that.

what windows app exactly will people trade for few hours of battery life?

seriously, other than PC games, I don't know a single windows app I want to run on a tablet form factor.

Maybe not, but they designed it so that it's a tablet/ultrabook hybrid. Do your research on the couch in tablet format, then move to the kitchen table to write it up in Microsoft Word. Read and write emails during a bathroom break, then create an insightful business presentation in Microsoft Powerpoint (don't forget to wash your hands)!

So what will happen when you have Word open in "ultrabook"/desktop mode, but then start using the Surface in tablet mode? Is the same instance of Word still open? Is its interface the same? These are the type of things that MS hasn't proven themselves good at designing. MS tends to overcomplicate their UI (Ribbon etc) and in my opinion, a tablet tends to benefit best from focus and simplicity.

Nor is it likely to be priced at or under $499.