Every programmer worth his/her salt has a copy of .Net reflector somewhere close. It is way better than having a peek by "View source".
In case someone points out about an xbap, you only have to search in your application data and local settings\application directories to find the assemblies for an xbap application.
Most people don't do any kind of obfuscation on their code and it is still possible to guess something from obfuscated code.