[ArtMonkDrillz]

I feel like this rule would probably also favor the NFC in terms of useable sites a bit too much to be fair to the rest of the league.

Assuming that the championship games are played at sites that represent the conference, meaning that you won't have the NFC game in an AFC city, there are more possible sites for the NFC to use. This is also assuming you want to try to eliminate the weather as a factor, like they do with the Super Bowl.
For the NFC the following teams' stadiums could host: Arizona, Atlanta, Dallas (once the new stadium is built), Detroit, Minnesota, New Orleans, St. Louis, and Tampa Bay.
For the AFC you have: San Diego, Indy, Houston, Miami, and Jacksonville.

I don't know if this is a big deal, but I would think that it's something they have to consider.
Of course the new commissioner's office will probably just schedule all playoff games and the Super Bowl in other countries by the year 2014, so then it won't really matter at all.