I migrated Silverlight TruckWars to the SL Beta 2. I started working on TruckWars as a way to learn Silverlight back in the Alpha last year. Being a Microsoft product, there have been two more betas (with plenty of breaking changes), but I've finally migrated it.
Things of note - Beta 1 started supporting buttons, which obviously simplified things. For example, it helped me remove keyboard input. It also had some subtle changes that affected the gameplay. Also, there still is no dropdown. Before I was using an HTML dropdown to select the levels. Rather than jump through hoops, I just ceded the dropdown part until the next release.
Because the code has been migrated from an alpha, to a beta, to another beta, it's becoming pretty screwy. Not the best, most agile code out there, but good for a demo of what cool stuff Silverlight can do. You can play it here.