Thanks to the efforts of the KDE4-OpenSolaris group -- among whom I number myself, hnhn, Hajma, and Ben as well as various testers and supporters -- the KDE SC 4.4 beta1 (version number 4.3.80) is available as OpenSolaris IPS packages. Note that beta2 has been released already so there is more updating to do. In the course of the beta cycles, the amount of patching that needs dealing with tends to drop -- at least as long as there are no large code drops.
Speaking of large code drops, Dario tries to explain polkit -- a good thing, but I'm still not sure if this thing actually exists for me or not.
Packages: there is an IPS server hosting packages for 4.3.80. This is still my FreeBSD port of the pkg.depotd, so I do hope it remains compatible with the pkg command -- pkg is still under interesting development, and it does suffer from API changes every now and then. In theory, you can just add this IPS server (say, as kdedev-ips .. oh, hang on, that is one of the things that has changed: I don't think you can free-form name your IPS servers anymore). This should be a straightforward upgrade of your existing KDE packages.
Korona 4.3.80: there is a new release of the OpenSolaris live CD Korona (by Pavel Heimlich). It is available from genunix.org. Genunix is where you can find all of the different OSOL distributions and specializations. You can also get Belenix there, which is the KDE4-with-gcc distribution of OSOL. Note that the most recent distro's are based on an OSOL with ZFS data deduplication, which may help in reducing disk space requirements if you have virtual machines or multiple source trees checked out.
Next steps in KDE4 on OpenSolaris are bumping everything to beta2 and plenty of runtime testing. I'm pretty happy with the stability of the desktop and KDE PIM right now, even Akonadi works; I think my main annoyance is with hangups in name resolution. Konqueror, for instance, regularly hangs (up to 10 seconds) in a dbus call (yay pstack). I think that's either name resolution or favicon handling.