Ask HN: What's next after Windows 7 for Enterprises?

I get that Windows 8 is aimed at tablets and that it's still basically Windows 7 for desktop users (except you have to bounce between 2 main screens now).

Most medium/large enterprise, certainly in the US and Western Europe run Windows in the vast majority of cases. They tend to lag behind the current releases, I know plenty of companies still on XP, only just considering an update to Win 7 in 1-3 years.

But what Windows 8 leaves me struggling to visualize, is what OS will be on desktop systems ( a market that will soon start to shrink) in Enterprises in 5-10 years time? Is Windows 8 going to be ignored like Vista was and the real Enterprise upgrade going to be Windows 9 in another 3-4 years?

Or are Microsoft accepting that they've lost the fight at the very bottom, the startups are all using OS X/Ubuntu/Google Apps and they're making one last play for the tablet market to make that and the XBox their main revenue generators?

Have Microsoft made any hints? If I were making IT decisions in a Microsoft shop, I'd be scratching my head at this point.