I use mostly Om2008.12 with my own tweaks (something along the lines of what Kustomizer http://wiki.openmoko.org/wiki/Kustomizer brings along) to a quite ok success. Only the slowness of the Qtopia apps is really annoying.
I'm now dual-booting Om2008.12 and Debian, with interest to moving to Debian completely. It needs some heavy customization still, but with a bit more proper SMS software I could already move.
The nice thing is that I've a separate data partition on my 8GB MicroSD card, so that I can access eg. OpenStreetMap data and music files from either distribution via TangoGPS and player software.