I did it...easy peasy!
just fill out the app, send the documentation they ask for (I think I sent my passport, my mother's expired British passport, my birth certificate[?] and her LONG form birth certificate), make sure you pay their fee, and presto, you're a British citizen! It took me about 4 months start to finish, but I've heard of others that received their registrations sooner, and some that took longer. Once you receive your certificate of registration, you can apply for a UK passport.