Ok, it looks like all the action is on the 4 bit arduino library. Lots of people are working on that and the library compiled out of the box for me, and apparently it is supporting multiple lines and 20x4 displays. And it uses less pins than the 8 bit one:
http://www.arduino.cc/playground/Code/LCD4BitLibrary 
It looks like the most promising solution at this point in time, better than the 8 bit solution.