Check out this demo.
While touch sensing is commonplace for single points of contact, multi-touch sensing enables a user to interact with a system with more than one finger at a time, as in chording and bi-manual operations. Such sensing devices are inherently also able to accommodate multiple users simultaneously, which is especially useful for larger interaction scenarios such as interactive walls and tabletops.
Sounds nice, looks WAY better. The demo features several applications which are quite novel, I particularly liked the demo interaction with the swirly stuff (imagine using that to create art) and the section where they make a collage of photos, dragging them back and forth and dynamically resizing them on the fly.