If you have any Xbox live games that your halfway thru your screwed. All your regular apps you can plug your phone to your computer and open Zune. If you don't have Zune just download it connect phone and log into Zune with your live id. Under your account you can see your purchase history (free apps are here to). Just re download to your phone all your apps that you want (you don't have to pay again). Some apps are no longer with us so there might be a few you can't replace.
Now MS needs to give us cloud storage for our games. It seems like it took me 2 years to get 200 gs on angry birds. If my phone would've died right before I got it and I had to start over I would've had a s@#t fit.
Thanks.... I heard you can party chat with your friends with Mango but it's not available now. I kinda figured the Nov 15th dash update would bring this feature. Since cloud gaming is also coming to the Xbox it would make sense to roll them out together.