All of Palm's GSM phones (since the 600 and except for the 500v) have supported 850/900/1800/1900. The 750 and Treo Pro have also had 3G support on 850/1900/2100. T-Mobile, in the US, uses 1700, is the only carrier worldwide to do so, and few non-T-Mo-branded phones support it.
Originally Posted by ipsi
I also found this, from palm.com:
While it's hard to be sure, I'm hoping that means a comparable radio to the 750 and Pro.
scheduled to be available first in the United States exclusively from Sprint in the first half of 2009, and will be followed by a world-ready UMTS version for other regions.