Wow, congratulations! Really nice work! I remember Adam giving it a try and having trouble, I'm impressed that you got it all figured out. Very, very useful ability. Also, it points out how the iLiad is really a very capable multi-purpose tool.
Re: pressure data:
The pressure data is definitely available. I don't know whether pressure got written into the new community-developed iLiad touchpad driver or not. That is, the question is whether the driver passes along pressure data to other applications. If I get a chance I'll look in the source code and see.
In any case, the second half is, even if the data is available from the driver, you still have to change the user programs to take advantage of the pressure data. As far as I know, no one has tried to do this yet.
Re: tilt data:
The iLiad's Wacom tablet definitely does not provide tilt data. It's not even tilt-capable. We don't know exactly what the hardware is, but it responds to the TabletPC protocol so it's probably similar. I actually corresponded with a Wacom VP of Engineering, who confirmed that the TabletPC Linux driver is a pretty complete implementation. He also confirmed that the iLiad's Wacom tablet doesn't do tilt.
Here's the
thread nekokami mentioned. It dates back to when we were working on the "calibrate" utility and the new iLiad tablet driver. It pretty much covers the tilt topic from every angle, and the conclusion is that it's just not possible.

Sad, too, I really wanted tilt.