You're two days early
Unless there are some seriously dodgy back-room deals, Win7 won't grab that much. Mobile!=Desktop, MS cannot manipulate that market so easily. The sheer number of players, markets and the fact that fashion plays a big part are all against them stitching up the mobile market like they have done to the desktop PC market.
And look at the traction Android is getting beyond the phone (e.g. tablets). Sure, many of these devices are under-powered and not great, but these are companies doing it off their own bat and for CHEAP! Win7 won't be able to apply loads of proprietary and anti-competitive hooks as it won't work with other people's devices.
And these companies will get better and better at making competing products, innovating and sniffing out the market.
As for those bleating about "integration", with more being consumed via the browser (and assuming the apps are written to the standards and not proprietary extension) it matters not one whit the client OS. Also, if governments follow through on their threats and go F/OSS, then the barriers to entry and proprietary APIs (the only thing keeping MS entrenched) come tumbling down. People are then free to choose of capability and I am sorry, no one in their right might picks MS based on capability.
MS is the enforced choice due to lock-in. Not a choice made with freedom.