I'll be working on a large project that needs some pretty complex logic piece inside some embedded hardware (based on XScale).
I started thinking of using Java but now I'm inclined to use Mono instead.
The main reason, beyond my personal preferences as I've been a Mono Hacker for years now, is that I need a royalty free solution and, AFAIK, GNU Classpath and open/free JVMs aren't complete enough for what I need to do, that would require something like Tomcat 5 + iText + some free implementation of Secure XML Web Services.
Mono at the other hand is not fully ported to ARM/XScale... :(
Some hard work lies in my path ahead, I'm quite sure...