This is nothing like confirmed, and I've got no idea who exactly is behind this project and what's its name but I just stumbled upon a posting on the Openmoko Community ML by FSO's Michael Lauer stating that there is a “project that tries to supply an PCB-replacement for
existing GTA02”. And yeah, UMTS is there and it is supposed to deliver “roughly the power of a Beagle Board”. While this is not as interesting as another open phone would be (replacing the small GTA02 screen with its even smaller finger touchable area, this still sounds pretty cool.
BTW: The same ML posting contains some information regarding good old dead GTA03.
P.S.: If you are looking for the FOSDEM slides mentioned, get them there.