I work with the Professor who completely redid WPIlib (named after my school, WPI) for the new controller. As a side note, I didn't work on WPIlib, just worked with him as one of his TA's. The new controller is a National Instruments FPGA with multiple modules prebuilt/coded for FIRST use. WPIlib has been transfered from its original C for the old FIRST/VEX controllers to Java for the new one. So in other words - learn Java!
WPIlib is ridiculously easy to learn - the function naming convention is very easy, and with the new module based approach you can literally make objects in code that represent a part of your robot.
For some reason the only official WPIlib site that I could find (
here) only contains information about the old WPIlib - they may be keeping it a secret for the competition, so don't point too many people towards this post :-).