As you could see from the SeaRay preview Elop showed to the press, Nokia is there way sooner than anyone ever thought.
WP7 in my opinion offers a very strong user experience, and has a brilliant future if backed properly. What WP7 did not have, but now does, is a manufacturer that is full-time behind it. And that manufacturer is Nokia.
I have to say that dropping MeeGo would be a grave mistake for Nokia, but WP7 is not something to be overlooked. I did not hear one person, one person in one year to be disappointed with their WP7 handsets. And I know a lot of people who own WP7 devices.
Every manufacturer has waited for others to start promoting WP7 before they took a chance with it. Everyone was waiting for Samsung to be the first to blow the horn, which did not happen. Then silently, WP7 devices dropped their prices to nearly half the launch price.
Everyone showed off their Android devices but no one bothered with WP7 devices. Everybody knows that you get Google Maps navigation with Android, or Angry Birds, or whatever attracts the customers more. There are alternatives for WP7 too, but no one is putting any significant effort behind promoting them. And that's why many people who are looking to buy a smartphone never heard of WP7.
With Nokia being the primary WP7 manufacturer, things are going to change. There are a few things that Nokia does better than anyone else on the planet.
1) Build the best hardware, no doubt
2) Market their products like no one does. They have contests, they offer trials(trough WOMWorld) and many more such ways.
So the question is who's saving who here? My guess is Nokia is saving Microsoft's WP7 with it's existing network of advertising, manufacturing, and most important selling.