Yes, this is confirmation of the demise of meego and qt (in the phone space at least), which is sad and disappointing.

But Nokia is in a very different position to SGi and is doing this deal for different reasons. Nokia urgently needs a decent OS - Symbian is the main reason Nokia has such a weak market position in smartphones. You can debate the merits of WP7 but its better than Symbian.

The next issue is apps and ecosystem. This might not work out, but a Nokia-supported WP7 market place has some chance of reaching critical mass and fighting it out with RIM and HP for third position after itunes and android.