ive never heard of that.
and it dosnt really make sense. the game devoloper sells tracks online so why would they make a feature allowing you to import your own songs? who knows though, maybe.
i would get rockband cause its fuckin kickass.
just remember you cant use periphrials from rockbank for guitar hero, but im pretty sure you can use guitar hero guitars for rockbank.
i might be talking out of my anus though, so google to be sure