Yep, there's now a hip-hop song all about SWTOR entitled Cold Republic, created by the already-established hip-hop artist Richie Branson. It seems Richie enjoys playing his Empire character Kazen on the Ven Zallow RP-PVP so much that he stopped playing just long enough to write and record a song about it.
According to his website, he plans to create more SWTOR-related songs, using samples from the game itself.
*Most of these items are not real.
[Thanks Matt for the tip!]