Yeah Boomdizzle was primarily the name of the website, it was started back in 08 as basically an internet record label/social hip hop site. The program "Boomdizzle" had been in beta testing for a while,(most programs go through that...) but the official release of it wasn't until this year.
I've heard of a couple of other programs with the same idea but this is the first that I've heard anymore about. The others just seemed to die off.
I like the idea though, being able to collab in real time is awesome...how many people that will actually do it is another story. It's a great tool imo.