Since the end of Season 1 new BSG has aired just about everywhere, I guess spoilers are okay, but just in case, ye be warned, here there be spoliers:
I'm pretty sure there has never been an official BSG roleplaying game. I think it would be pretty easy to do, especially with a lot of the stuff in d20 Future. From a game mechanic perspective, BSG is pretty easy, since it's standard space opera: hyperdrives and capitol ships and starfighters, robots and guns, all off the shelf parts as far as rules are concerned. Personally I'd use either Wound/Vitality because of how combat has been shown, and how one lucky or well placed hit can really seriously mess up even a high level character (like Boomer attempting to assassinate Adama).
Nothing in the way of anything supernatural (generally, there was the weird Iblis/Angels stuff from old Galactica, and the ancient prophecy regarding Pres. Roslin in new Galactica, but nothing in the way of powers for PC's or 99.9% of NPC's). No new alien races really to worry about, especially in New Galactica (at most, the various Cylon models would need stats).
The trickiest thing I can think of is how to treat Humano-Cylons from new BSG, since biosynthetic robots from d20F just isn't close enough (I think biosynthetics were meant more for things like androids from Aliens). Humano-Cylons are probably best treated as humans with a sort of "Cylon Replica" template that makes the Cylons their primary allegiance and it cannot be changed, lets them stay in contact with other Cylons (subject to jamming and interference), they are sterile, and they suffer a double damage from any ability damage caused by radiation (judging by the events at Ragnar Anchorage during the mini-series.)
Licensed Sci-Fi RPG's that I can think of: Farscape, Stargate SG-1, Star Wars (d6 and d20), Star Trek (FASA, Last Unicorn, and Decipher versions, and the Prime Directive RPG based on the Starfleet Battles sub-license), Babylon 5 (Babylon Project and Mongoose d20 Versions), and Trigun (yeah, it's anime, but a sci-fi anime) and Men In Black.