IIRC the kaffe open source JVM can run on xscale linux (but was not complete last time I checked). You can get something called J9 from IBM for very little money (IIRC even for free while doing development if you download some workshop version from them).
And then there is JamVM:
http://jamvm.sourceforge.net/
SableVM has been reportet to work on xscale, too:
http://sablevm.org/
There is another VM at the 1.3 language level originally developed by acunia systems called wonka but their site seems to be down and I cannot remember who took over development.
Given enough time and a repaired Iliad I will eventually try these. I had briefly looked at superwaba a long time ago and of what I remember they had their own API which was not compatible with the usual JDK classes, it would be nice if anybody (cervezas?) could look into that and determine if sourcecode would still be reusable.