Almann Goo released version 0.6.0.0 of JaCIL on Saturday. The goal of JaCIL is basically to be a reverse ikvmc, it converts .NET assemblies into Java jars.
The binary distribution includes a couple of demos. Naturally I had to try and run them on IKVM :-) I ran into two known IKVM bugs, the first being that JaCIL generates a class and prior to Java 1.5 this wasn't a valid class name, but since Java 1.5 the class name space has been significantly enlarged, almost all checks have been removed. The second bug was that Java classes with both a Finalize() and finalize() method would be compiled incorrectly (under the covers IKVM generates a Finalize() method that overrides System.Object::Finalize and calls java.lang.Object::finalize), I've added support for this by renaming the generated Finalize method when it is necessary.
JaCIL isn't yet at the point where it can compile the ikvmc generated assembly[*], but maybe we'll eventually be able to run Java on .NET on Java on .NET on Java on .NET on Java... ;-)
[*] If you try it, you'll likely to run into an IKVM limitation. JaCIL is a .NET application and uses an ikvmc compiled version of ObjectWeb ASM and currently, IKVM.Runtime.dll gets confused if multiple versions of IKVM.GNU.Classpath.dll are loaded in the AppDomain.