Just so everybody's on the same page, Windows Phone 7 (WP7) is NOT Windows Mobile (WM). I've used Windows Mobile 6.x and it's nowhere near Widows Phone 7. They're both made by Microsoft, yes, but that's like comparing Windows 98 to Windows 7.
Windows Phone 7 was announced just last year and was made available locally just this year, so that 2009 article may no longer reflect the current phone OS climate. Maybe this move by Nokia would somehow springboard WP7 into real existence.
I don't work for MS, but I still believe that we should give credit where it is deserved. Besides, I love my Android phone so much right now. :D
As for the Xbox Live integration, you'd be happy to know that it's built into WP7:
http://www.xbox.com/en-US/Live/Mobile/Home