There is a huge world of obsessive Star Wars geeks out there. If you only knew about Princess Leia after googling, then I take it you are oblivious to this. But please be warned, you really are taking on a lot if you use a name that only really came into being via this film.
My niece is a Leia. We initially thought she was called Leah, as her dh has Jewish heritage, and then were a bit because of Star Wars. However the connection soon wore off (she's 12) and I don't think it's caused her any issues. Leia did exist as a name pre Star Wars too.
Leia is at the top of my shortlist at the moment, I love it and don't mind the star wars connection at all but am slightly concerned about being judged by more fanatical friends and family of ours who might tease us for naming our child Leia! Thoughts? :S