For everything you wanted to know about mobile PDF support, see
Q&A: What PDF version for eBooks?. The bottom line is that whatever Apple supports Adobe tries to support too.
Bill McCoy mentions that RMSDK 9.1 (released last December) supports JPEG 2000 images, and I guess I am a bit surprised that the PRS-950 is using an earlier version of mobile ADE. Only a bit, because Sony has a "don't spend any money on software development" policy for their Readers.