One does not have touch screen, the other has it.
That’s (honestly!) seems to be the only difference between the two.
The new PDA’s adds the wireless feature as a distinction (especially Wifi 802.11b or g).
I have no idea which form will be more attractive. Better yet, which one will be more functionally attractive. I’m sensing that it has the potential of a “PC advent” like scenario of the 80s.
Until then, I’m waiting for more news on Openmoko. 🙂