Originally the plan was that Anderson Silva had to get past Chael Sonnen AND Vitor Belfort before vacating the title. According to UFC President Dana White, he will have cleaned out the division and it would be time for him to move up to the 205 division. It would appear that Dana changed his mind, because he said at the recent UFC Fan Expo, “He’s got to get through this fight with Chael, and then we’re going to start talking about him going to 205.”
No word on why he changed his mind, but the decision makes a lot of sense from a promotions standpoint. The light heavyweight division has no one clear dominate fighter, so there’s a wealth of new challenges for Anderson Silva…all of which could headline and sell out a show. When he vacates the title, the UFC will need a BIG match to determine a new champion. If you look at the talent they have and/or might come close to signing, I can’t think of a bigger fight that Vitor Belfort vs. current Strikeforce champ Jake Shield.
It would also leave two fighter left for Anderson to challenge if 205 doesn’t work out for him (doubtful), or he just wants to step down to 185 on occasion to remind everyone what his name is.