I've got a Palm Tungsten T3, and it syncs fine. According to the iSync supported devices page, all Tungstens and Zires are supported natively by iSync.
I know that the Windows Mobile ones don't, but do ones which run the palm software?
I have a Palm T|X. Works fine with iSync, however, you have to initiate a sync from the Palm (HotSync). iSync uses a "conduit" through the Palm Desktop software.
Treo 700p works syncs almost perfectly once you get it setup...only flaw I've come across is iCal and my Palm can't see each other's alarms. (Thankfully, it syncs due dates and everything else.)
i have a qtek 9100 with win mobile 5.0 and i use missing sync works very very well.... bluetooth took a bit to set up but the support page was really good....