The ESPN announcement of switching Sunday's game amongst a few others from ESPN 2 to ESPN is significant. Not too long ago, you'd be hard pressed to even be able to find a MLS game televised at all. If this momentum continues and the TV deals get greater, you can theoretically do a similar model to the NFL. Profit sharing that TV money to create a higher salary cap. That keeps the foundation of "ever team has a chance" but also forces teams to spend to compete. It's not a perfect system, but some variation of it could work for MLS.
One of the things MLS has badly needed is to get the ESPN hype machine behind the league. That finally seems to be happening.