The Asus Eee PC T91MT is an Atom Z520-based unit, using a tablet construction for the 8.9" LED-backlit display. As you'd expect from a multi-touch device, it's aimed at providing useful manipulation with hands alone -- though Asus includes a stylus with it as well. Multi-touch aside, you'll be missing other features with the default configuration including 1GB of RAM and only 32GB of storage (granted it is an SSD).
The system looks quite nice in the demo shots, and judging from the listed weight (less than 1kg) it will be easy to carry on the move. It ships with Windows 7, which has a wide variety of multi-touch features, such as gesture support. Asus' Eee PC T91MT marks another first for the company, which gave rise to the netbook market a few years back, and other venders can be expected to follow suit soon enough.