i just discovered Guitar Pro5:
http://www.guitar-pro.com
found reference to it in one of the youtube video of this kid.
the program is amazing... compete tablature, plus accompaniment instruments (audio/midi).
there are websites that have all the Guitar Pro tab files, that you can find just about any song you want to learn to play.
i like this site:
http://www.gtabs.org/
on day 2 of the 15 day free trial.. definitely worth buying. runs great on my mac.
fight the plug!