in a new interview w/ Degenki magazine, Nomura gave us some specifics on what exactly will be coming to us in the NA release of BBS
-You get a certain secret someone's Keyblade after defeating him. (i hope he means Vanitus =3 well, i suppose MX's looks pretty damn cool too)
-No new secret movie on BBS but there WILL be one on RE:Coded.
-Some movements like Mega Flare will be modified to lower their power.
-As Nomura says in the interview "The new secret boss will be like how Lingering Sentiment was to KH2FM. You will think it's impossible that that can happen at that time of the story, but it actually happens." So yeah, confirming LS and the new secret boss are canon.