So this mouse has many buttons. It even has not-buttons. The ROCCAT Tyon has 31 user-customizable functions mapped over 16 buttons. The "Tyon Xcelerator", near its thumb buttons, is an analog switch designed for functions such as throttle or vertical movement. The "Dorsal Fin" is a switch that tilts left and right, like a tilt wheel, except that it also has a tilting mouse wheel.
I guess you can never have too many tilt functions.
Yo Cat, Heard You Like Buttons…
In short, ROCCAT has basically put as many functions on that mouse as they believe comfortable. Personally, I think the "Xcelerator" could be quite useful for games, like Battlefield: Bad Company 2 with its UAV, where you need to move in three dimensions and rotate in two dimensions, at the same time. That just leaves about 30 other functions to think about.
The ROCCAT Tyon is "coming soon" for 99.99 Euros (~$136 USD).