Does anyone know of a .net wrapper around either python or java Google App Engine services?
Any help appreciated // :)
I don't think it's impossible to run .net on GAE. At least, it's not impossible to run something that was generated from .net sources or interprets them at runtime. Just think about Ruby or Python, both work on the JVM (using JRuby and Jython). You'll probably have to look for something similar or try to cross-compile you .net code to Java class files.
Here is a related question: Why doesn’t Sun do a C# to Java byte code compiler?. Some people suggest using JaCIL or jsc. I didn't try those myself, but I'd bet you'll have to get your hands dirty to get something to work.