Palm doesn't seem to be doing much to innovate in the hardware side of things however Sony might take the platform to a new level again. Brighthand has some information on Sony's latest announced Clie PEG PEG-UX50, the clamshell-shaped PDA will run Sony's own-made Arm processor which they call the "Handheld Engine":

The Clie PEG-UX50 will use Palm OS version 5.2 and run on what Sony calls its Handheld Engine. The Handheld Engine appears to consist of a Sony-made ARM926 based processor, a Digital Signal Processor (DSP), and a CXD2230GA graphics accelerator chip. Sony says this has been optimized for handheld devices, focusing on battery life and speed, and it will allow Movie Player to play video at 30 fps. The exact frequency of the processor varies between 8 MHz and 123 MHz, depending on the demand being placed on it.