The SWTOR team over at BioWare just posted a small cartel pack comming with the patch. Check it out: 1y3r4l
Bolster your defenses with the galaxy’s newest gear, including never-before-seen armor, vehicles, weapons, and more! Lead a covert strike wearing the new Silent Warden Jedi robes, channel your inner fighter pack in the in-game Cartel Market!
The other stuff about 5.1 were things we already know – 5 new uprisings, Master mode chapters.