SV, I don't know how often you play but try fighting someone who knows what they're doing when they're using buu. Unless you're significantly better, you're going to have problems. Buu is faster, has a higher pl, has more hp, and has a crazy-strong beam. Thats why we don't use him. Unless buu is made to stand equal with the other characters (which I'm not sure will happen since he's friggin buu), people aren't going to use him and so the Janemba model will be wasted. Since 1.3 will make tons of people come back and many of the old players will return and will buy servers again, people will be forced to either play by our rules (which are fair for all) or go elsewhere (basically make their own server). Either way, Janemba won't be used often. The people who buy the servers are usually the people who care about the game, and the only players that actually care about the game are the..eh..."better players".
Thats why I'm thinking Cell would be a good choice.