Big name players follow the money...plain and simple, look at Jwong, he might like the game and all but he's a professional gamer first and a fan second. Others may follow suit as well.
I don't see any other gaming leagues dropping this amount of dough, so i'd say yeah this is one of the better outlets available for MK to surpass SF and their crossovers. MLG is making people notice MK, the SRK community is jelly from the attention MK is garnering from the Columbus tourney. As i said, this is only the beginning and if MK were to surpass SF, it will be with NRS support.
Actually if you read his twitter or watched any of the stream. It was clear as day Justin would rather be at NCR. He did it due to 1) being in EG and 2) to try to make the FGC and MLG work under the EG name. Look at his response to PR Rog and etc.
Also you're still thinking only NA/SA. Most of the international FGC fans are mainly SF fans. Look at Korea, Japan, UK, France, Kuwait, Guam etc etc. If you want MK to be bigger than SF out of some sense of "fuck you people who like capcom! go underdogs!" then this is meaningless to continue and I'm done.
Also to disprove your "big names follow the money". How many big name players from multiple games hit up MLG? Combofiend, ChrisG, Filipino Champ, Ricky Ortiz, and plenty of others did not even attend MLG and instead attended NCR. We can extend this further and look at James Chen, Ultradavid, Aris, Spooky, and plenty of other big names in the community that went to NCR instead.
Lastly its not MLG dropping this "amount of dough". Its sponsor dropping this amount of dough. Do you really think MLG put up that money? Y'know not Sony, WB, or any of the sponsors? Think about it. Sony was a sponsor for MLG but what games did they have on the PS3? I can tell you it wasn't the bread winner of Starcraft 2 or Halo.
Nobody is "jelly" of MK, and if you point out to random poster #1243 on SRK then again I repeat that Nobod(ies) is "jelly" of MK. I do not know what is this obsession of "beating SF" or "beating capcom". None of that shit is important. What is important to make your community/scene the biggest you can.
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TL;DR version
Money isn't the sure way to make your scene bigger. People can toss all the money they want behind a game/scene but that doesn't mean it will make your scene bigger and better. Look at previous games that have been at MLG (WoW, COD, Tekken, Smash, Gears etc etc) and tell me did they ever have the same staying power as Starcraft: Brood Wars? Let alone Starcraft 2.