Although KDE SC 4.4.0 isn't officially released yet (or there's no announcement on the dot yet), I've bumped the specfiles in the KDE4-OpenSolaris repository to 4.4.0 and kicked off a rebuild. That means that we should have new packages at about the same time that the major GNU/Linux distributions have them. The release candidate was pretty stable on OpenSolaris as long as you didn't (re)build any parts of it while logged in, but we'll probably be hearing enough bug reports in the next few months for OSOL. You can report problems to KDE's bugzilla with the OS set to Solaris, or use the OpenSolaris bug tracker and choose one of the KDE components there.
Of course, the whole future of OSOL is a little .. fuzzy. The Oracle / Sun takeover has caused a fair amount of shake-up in many of Sun's projects, but OSOL has not, as far as I know, been either committed-to or deprecated. We'll see.
In the wake (er, .. the bow shock wave, since I'm getting ahead of myself) of the release, Jos asks for something offensive and the KDE website has been re-vamped. Especially the latter is impressive, for breathing new life into the somewhat moribund site. I believe the call for help still applies as the rest of the content is polished and brought up-to-date.