Although I generally prefer third-party app providers, for something like this, and given the "quality" of the Android app, I think this is a good thing.

I mean, Microsoft obviously have a bigger investment in providing a smooth, deeply integrated app that is consistent with the platform's look and feel.

And given the low-quality apps Facebook has put out there in the past, I also think they have a higher bar as far as quality is concerned.

Also, I think Windows 8 - not WP8 or Windows 8 RT necessarily, but the whole family, including the desktop/laptop market - will end up having a significant user base.