I started a fundraising campaign for an application which
would provide fully customizable pie menus for any
application, translating the slice selection into key combos.
Details here: http://www.indiegogo.com/unipie
I’d appreciate if you’d share the url with anyone who might
be interested.
Any questions or suggestions are welcome! 
I’ve added a few examples:
http://www.zspline.net/files/UniPie_Examples.pdf
This seems very similar to the radial menu with the Wacom tablets.
The big thing you could improve over them is the ability to use lua scripting and delayed key strokes. and if possible macro recording.
For example in zbrush if I want to change my brush, I need to hit ‘b’ followed by ‘ct’ or the brush combo.
During my preliminary research I did stumble upon Wacom’s
implementation and it convinced me that it’s an idea
worth pursuing. Too bad my Bamboo don’t have it. :\
While key macro support should be in the first release,
I’m not sure about actual macro recording. We’ll see how
difficult it is to manually compose a macro as a dynamic
list of “key;delay” pairs and plan from there.
Do you have examples for macros you’d actually use?
As for LUA, I’m a big fan of the language but I feel
integrating it would be an overkill and it could easily make
the app a resource hog.