It is possible to build it for N900. And provided that JSR 239 (OpenGL ES bindings), JSR 179 (Location API) and other important JSRs support would be compiled in this would bring a lot of quality apps to N900.

I did try to build it a year ago because I wanted to continue CloudGPS development on N900 when I got it but there were many problems with dependencies and my build environment. After quite a struggle I just decided to rewrite it from scratch in native C.

There is a lot of interest in bringing Java ME to N900 (many threads about that). Not everyone knows that phoneME would the best solution. Anyway I do care but I do not have enough free time to make it happen.