No new TX for a while. If ever. Supposedly there's been a rumor or two about an update, but nothing has come of it. Palm has focused their development cycles on Treos.
The news regarding Palm OS concerns the current iteration, Garnet (5.4.8). Basically they received a perpetual license to utilize Garnet as they pleased, with code edits, etc. Also, they have the right to emulate Garnet, as long as it passes a compatibility test from Access, the company who own the Palm OS.(But maybe not the name palm-it's tough to say. Very confusing wording on that, but Palm-the-hardware-company definitely owns most of those rights, as evidenced by the branding of their products.)
Anyhow, all this means one of two things. Either Palm is going to tweak Garnet half to death, or they are going to emulate (over Linux or WinMob or god knows what.) If they tweak they need to do some heavy tweaking, since EV-DO Rev A (High speed access being rolled out by Verizon and Sprint) and HSDPA (3g from Cingular) requires more complex multi-tasking than Palm OS can handle. Yes, Palm OS has such limited multi-tasking capability that it cannot handle the sort of voice/data pipelines that any dumbphone from LG or Samsung can run with ease. So emulation is the likely conclusion, with the first version out in (hopefully) a year or so.
What does all this mean? Well, with the treo being the bread and butter for Palm right now, I doubt there will be any new handheld releases until they get the high speed situation worked out. There'd be little to no reason to sell a "high end" palm with one OS, then release a smartphone with a totally different one; Palm isn't that resourceful of a company to be able to extend their support resources that far.
Sorry for the long and detailed post, I just wanted to get the information clarified as much as possible since there's a lot of confusion and information flying around.