The Zire 31 is expected to have a 160x160 pixel colour screen and a SD Card slot for memory expansion. The PDA will only have two application buttons instead of the usual four.
It is also expected to have Palm OS 5 and an ARM-based processor, maybe a 200MHz Intel Xscale for this low-end model.
The Zire 72 is a more advanced one with an integrated 1.3 megapixel camera for 640*480 shots. It will also have 64MB memory, of which 56MB is available to the user. It will also have buttons to activate the camera and to launch RealPlayer. It is also said to have Bluetooth connectivity.
According to market watcher Current Analysis' PDA specialist, Sam Bhavnani, the 72 drops the slider mechanism introduced with the Zire 71. It also features 32MB of RAM, up from the 71's 16MB.Source: The Register
Palm CEO Todd Bradley confirmed in interviews last month that the company would release new models in April.
Other new models anticipated from PalmOne include updates to the Tungsten T and E machines, and possibly a new, camera-less version of the Treo 600.