Psion announced today that Sony has licenced the Symbian operating system (based on Psion's EPOC OS) for use in wireless handheld devices. Full details have not been released, but an analyst has said that Symbian would license Sony's memory stick and Sony would use the Symbian OS in mobile devices.
This does not necessarily mean that Sony is "dumping" Palm. Remember that at one time IBM had licensed both Palm and WinCE, and that Nokia is a Palm licensee that has also ties to the Symbian group. I think that Sony is just trying to get their memory stick in as many devices as possible.