I "upgraded" my home computer to Fedora 9. "upgraded" because I reinstalled the OS instead of using the upgrade procedure. I have had so many issues with "partial" upgrades in the past (with any distro).
Although it is the preview/RC1 version, Fedora 9 is already as stable as a release IMHO. No issues so far, it feels more polished than Fedora 8. OpenJDK 1.6 is there. Firefox 3 is there. Not a single problem with kernel 2.6.25 (while I had plenty with the 2.6.24 ones).