For some time I have been wanting to help with tablet support in Inkscape. Things have finally come together enough for me to get started. We've had at least one RFE on this for a while (bug #171265)
The first step of this is in, and now has a preference setting to enable switching the Inkscape tool as different devices are used on the tablet (pen tip, eraser, mouse, etc.)
The implementation will probably need a bit of testing and refinement, but it should be ready for users to check out. The coding is not that difficult; most of the real effort is with figuring out the behavior that needs to happen.
At the moment the tool switched to is always the same for the same tool, but very shortly it will remember the last tool used. In the long run I'll probably be replacing our use of GdkInputDialog to provide easier configuration.
However, the main thing missing is how different tablet setups are configured. Multiple pens, multiple tablets, non-Wacom tablets, etc. That's where feedback from end-users and testers really comes in handy.