Microsoft can always work in the background on their own implementation of the services they will be temporarily borrowing from Nokia, and then they can just silently push out Nokia without endangering their portfolio. It wouldn't be the first time in Microsoft's history, one can actually say it's their most well known pattern... The only service they'd have a bit trouble replacing would be Maps given Nokia's ownership of Navteq. But then, it's not as if Navteq is the only game in town...

I still fail to see what Nokia gets out of this that is enough important to risk alienating their loyal customers, at least two years of severely lower profits, giving up on the middle portion of their portfolio (WP7 ain't gonna work on 250€ HW, profits included), axing the most used smartphone platform in the world by a large margin, axing arguably the best crossplatform development toolkit from the mobile space, killing of the Ovi service just as it was finally starting to gain some momentum, and essentially putting all their eggs in one basket... All that for a platform with abysmal market share and user interest, severely limited and completely controlled by Microsoft.

Whether WP7 succeeds or not, Microsoft won't suffer, they have a LOT of other sources of revenue and they can always muscle themselves back in the mobile market - they've been doing that for the past decade after destroying one by one mobile-oriented company. However, Nokia risks here a lot, by the time WP7's failure can be perceived they will be blown out of the mobile space and the best they will be able to hope for is the fate of Motorola, with no real platform or viable strategy as a backup. Even if the WP7 endeavor miraculously succeeds, Nokia will be having hard time to push enough devices to the market competing at the same thing with much cheaper manufacturers.

But ok, it's their choice, I guess... I won't be trying to save a company from itself. I'm just concerned what will we (the consumers/developers) be left with in the mobile space governed by a threesome consisting of a glorified virtual machine, walled garden and a flashy feature phone platform - all three of each striving their best to tie you into their individual isles and trying to control how would you use a device you've bought. So far, it doesn't look good...