You guys are putting waay too much thought into all this. Just in case none of you have done MLG online tournaments or gamebattles I'll clue you in.
Gamebattles is for fun. SOMETIMES theyll have a large cash tournament and there's always the possibility that some MLG reps. watch the leaderboards since a lot of them work on gamebattles as mods. or refs.
MLG Online does not replace lans and go-to live tournaments. They are done to see how popular the game is, to get initial placings for live tournaments, and too make money. You buy credits from them, enter the tournament and play for a cash prize with limited teams (usually between 32 and 64). I'm sure for a game like Brawl, there would be singles too. When someone wins after several weeks of playing, you get your prize and now MLG knows who you are and that increases chances for sponsorships, seedings, etc.
So my final thought is Stop Saying That MLG Online Tournaments For Brawl Are Bad!!! It's just an added bonus for those who can't get out to live tournaments or who just want to practice and dominate a game all together. So my recommendation, if you guys want Brawl to succeed, would be to participate in the gamebattles ladder for Brawl. As long as it's active and popular I guarantee MLG will hold online tournaments for it and if that's successful it will become a circuit game.
The same thing happened with COD 4. Everyone kept arguing for 3 months whether or not MLG would pick it up. Now there's a $5,000 tournament on MLG Online and those who denied COD 4 ever being picked up and eating there own words.