If you search for "Multi-touch" in the X2a help file, you'll get most of the info you need. Basically, what's supported is:
Adjust knobs, faders and buttons.
Scroll and zoom in the Track view.
Scroll both horizontally and vertically in the Console view.
Scroll in the Inspector.
Drag content from the Browser, with visual feedback.
Adjust MultiDock divider/splitter.
Control Bar Transport module touch support.
Arrange windows on the screen.
Trigger cells in the Matrix view.
Enable/disable steps in the step sequencer.
So yeah, you need a mouse too, and I'm sure that's true with most complex desktop applications. I would think they'll be adding support for other tasks. They definitely should add support for dragging clips, notes, etc., and a lot of other things.
btw, that looks like a cool device you bought. Even in the review on CNET, though, they said you should definitely add a mouse.