… so it isn’t launching anymore and displaying splash screen infinitely, or application launches then stops, and you have done only “usual” development, be cool… Wp7 is a new platform. We, early adopters, are here to catch them, report and hope it’ll be fixed in vnext.

Until then, check that you haven’t changed the name of assembly. Also, a symptom for this is this exception in output:

A first chance exception of type ‘System.Collections.Generic.KeyNotFoundException’ occurred in mscorlib.dll

TODO: figure out where wp7 issues are reported/recorded, see if isn’t there then create an issue for it. It’s probably a bug in emulator.