Microsoft and Intel have announced the UMPC (Ultra Mobile PC). On the surface, the UMPC appears to be a low end ($500-$1000) mini Tablet PC.
Pros: It's lightweight, weighing in around 2.5 pounds.
Too short a battery life (3 hours) to make it practical as a mobile device.
Too big for pockets (like an iPod or a Pocket PC), so how does one carry it?
More expensive than the top of the line iPod or Pocket PC and in the range of low end notebooks.
Ships with Windows XP, but it's an unknown about "upgrading" to Windows Vista.
Regardless of software included with the system, it appears that it will be inconvenient to use due to its form factor. For some reason it reminds me of an Etch-A-Sketch.