Nokia + WP7 is a good combination. It is a good move. Whether it will succeed or not is another story. I am unable to predict the future.

But I have a simple logic on why Nokia + WP7 is better compared to Nokia + Android.

Scenario : Burger stall (Android) and Pizza outlet (WP7) in town A

There are about 50 burger stalls in town A and no Pizza outlet at all. And if I am Nokia, does it make sense for me to open the 51st burger stall? Well, my burger will taste good because I have my secret recipe (good camera etc). It will definitely sell well but I still share my profit pie with other burger stall.

Although my burger is the best, if I don't open my stall tomorrow, I lose business. My profit pie will be snatched by others. (this refers to regular updates etc)

If I open a Pizza outlet, I will be the 1st person. Well, my pizza will not outsell burgers as burgers are more popular. But hey, I am the only one selling pizza, and there are enough people who likes it (although not as much as burger lovers). I don't need to share my profit pie. I still make money. I will come up with new recipe and will try my level best to promote my pizza so that more people leave burger for pizza.

Tomorrow if I decide to close shop for a day, I don't need to worry of losing my business (this refers to irregular updates etc)

I know that if my pizza business is good, there will be more people who opens pizza outlet. Before that happens, I can either patent it (get exclusivity) and franchise it or; I can let new players to come in because my pizza business is already established. When pizza is mentioned, everyone will remember my outlet.

Now, to those who feels, "why not both burger and pizza at the same time?" I don't have enough resources. I rather concentrate on one thing and do it well rather than stepping in everywhere and be average everywhere.