Here's more bad news for the PalmOS (Until it moved to a Linux base): Carriers are tired of supporting multiple OSes. Vodafone specifically wants WM, Symbian, and Linux only (though it's likely they won't be turning away the iPhone when given the chance). The "Linux" is sort of amusing to me, though, as I suspect that's going to be an awfully big umbrella in the near future.
Vodafone, the world’s largest mobile phone company in terms of revenue, has been leading a push to limit the number of operating systems, declaring in November that it would eventually sell only phones that ran on Microsoft’s Windows Mobile, Symbian Series 60 or Linux. For more than a year, NTT DoCoMo of Japan has concentrated on Symbian, a privately held British-based company in which Nokia of Finland has a nearly 50 percent stake, and Linux.