The first Windows 8 advertisement danced its way across television screens across America during breaks in NFL football action on Sunday, and guess what? It was all about touch. Touch and tiles.

That should shock no one. Touch and tiles, that’s the essence of Windows 8’s new user interface. Swap out the new UI – Microsoft now calls it the “Modern UI” – with the Windows 7 “Start” menu and all you’d be left with are a few cosmetic changes along with some minor improvements under the hood. So if Windows 8 compels consumers to run out and buy PCs this holiday season, it will be because Modern UI is a hit. And Modern UI is all about – I’ll say it again – touch and tiles.

Pretty simple. And yet a surprising number of the Windows 8 PCs now making their way to store shelves in preparation for the October 26 launch date aren’t touch enabled. The reason: PC makers are worried that most consumers won’t be willing to shell out the money for a new laptop with touch, which adds about $100 to the price of a system.

It’s hard to fault them entirely for that line of reasoning. While there will be some Windows 8-based Ultrabooks available at mainstream, high-volume price points, many of the coolest, most lust-inducing models will be priced north of $1,000. Which means they’re not going to sell that many of them.

So the PC vendors are caught in bit of a Catch 22: They can build Windows 8 systems at prices that most consumers are willing to pay. Or they can build Windows 8 systems that most consumers will really want to buy. But they’re having trouble compressing both into the same systems – which means there’ll be a firesale for non-touch laptops come January.

Read the entire column on InformationWeek.com