I found this site last night and thought it would be helpful to many here...we (hubby and I) are in pretty high gear right now, because as of yesterday, he has the right to register as a British citizen!!!! We are getting all the info together and hoping he will have his UK passport by end of summer/early fall in prep for next spring's move, this is so exciting!
The link is
http://www.richw.org/dualcit/faq.html . The gentleman who does the site states pretty clearly he is not a lawyer, but he is a dual US/Canadian citizen, so has been through a lot of this himself and consulted with many people.
Since I definitely plan to become a UK citizen as soon as I can, but absolutely want to keep my US citizenship as well, I found this stuff pretty helpful.