well, syncing through GNOME's Opensync has always been possible, I thought you were aware... To do so, you have to use the Mack connectivity Pack to route the traffic from your GPRS connection through a Bluetooth PPP with your linux box. A fake GPRS data connection has tobe created on the phone, usin the IP data of the peer, and then, use the over the air sync tool. Overall, a lot of hacking just for syncing!!!!!
But there are problems:
The sync tool of the phone itself is really bad, fails to clanly sync. I tried GPRS syncing with Over the Air with free Internet syncing servers to test the program under ideal conditions, as this is the way it was designed to work, and it sucks...
Opensync is only officially present on GNOME.
For KDE, actually, Kitchensync is gonna use opensync as its syncing engine, but I think this is going to be implemented on KDE4. Of course, you can try the svn versions. I was unable to compile them and ran into binaries for SuSE, wich resulted in a nightmare of dependencies, and when finally installed, the program created the pair, but did nothing when pressing the sync button...
Gelobt sei was Hart macht...