A
legal ad-supported p2p music download company. should prove interesting.
For those of you wondering "mpq" is an archive format created by Mike O'Brien for use in Blizzard games; it can store all kinds of stuff and is quite versitile. That being said there's quite a lot of talented hax0rs out there that know a lot about MPQ (anyone heard of diablo trainers etc?). I think its going to be about 20 minutes after the service launches that the protection scheme gets hacked and you're no longer hindered by the five-listen limit.
Of course if you're willing to download a crack for your free legally acquired music you're probably willing to just download the music elsewhere.