Brazil's SporTV is reporting that former UFC Light Heavyweight champ Rashad Evans and Brazilian legend Antonio "Little Nog" Rogerio Nogueira have verbally agreed to a bout to be held on February 2, 2013 on Super Bowl weekend. The UFC traditionally runs a big card in Las Vegas that weekend. Presumably it could be UFC 156 but that is assuming that there will not be a numbered UFC event in January following UFC 155 on December 29, 2012.
SporTV is only claiming a verbal agreement for the fight with neither fighter having signed but they say they have multiple reliable sources for the information. It's important to note that this is exactly the kind of fight announcement that often ends up not panning out. It's highly likely that all of SporTV's sources are coming out of one camp.
The UFC often floats match ideas past fighters and their camps and secures verbal agreements from one side before talking to the other. Sometimes they get verbal agreements from both camps and still don't go forward with the fight. Remember no UFC match-up is official until it's announced by the UFC.
No headliner is rumored for this event yet, but if the UFC managed to book an Anderson Silva vs Georges St. Pierre superfight, February, 2013 would be an ideal time to make it happen.