What the mobile (or smartphone) boom should have shown every nerd on the face of the planet: nobody outside of /. gives a shit about "reputation" when picking up a new phone or tablet. If Microsoft manages to launch a smartphone that is affordable (i.e not priced above an iPhone) and manages to make Windows-not-metro-for-fucks-sake-please-dear-god-please-stop-reminding-us usable on a touch device and the desktop at the same time, all that bad nerd press from the last 15-20 years will mean diddly squat for their sales figures.
The non nerdy friends and colleagues I have all pretty much agree on what is important in a new phone: camera (especially camera vs. dim light conditions), app store inventory (games mostly), fb app, twitter app, instagram app. Who made the device is of very little concern.
Now, with a one OS to rule all platforms approach, they might even be able to add some of that Apple just-works magic to their portfolio, which is not to be scuffed at.
And I agree, MS is not old MS anymore. They've been forced to try and keep up rather than the old buy-and-extinguish strategy, at least in the mobile and touch device market, and I think it's been good for them.