This is a seriously good discussion.
In terms of international prestige people regard Juve, Milan, Inter and Roma to be 'big teams' historically. Lazio, Fiorentina, Napoli and even Palermo have a higher reputation than the rest of the league, too. I've mentioned before that all of those teams have a decent place to start from in terms of building an international following. As pointed out above Roma has 7 million followers on facebook. That's a great position for a team that hasn't challenged for anything in a generation.
In terms of the league becoming competitive I'd like to see Milan being bought by these Chinese guys while Napoli and Roma keep up their progress and get to a position to challenge, doing it the hard way. Then with the added audience the other teams I mentioned would gradually improve with the league as a whole. There are a couple of other things to consider, though.
- The Europa League: The league needs to do something (although I have no idea what) to make teams take it seriously. More coefficient points mean we get our fourth CL place back and with it the added cash.
- Stadiums: To be honest I think Roma and Milan or whoever just need to get it done somehow. Bribe whoever they need to and just sort it out. I love the current old-school stadiums we have but they don't fit the modern game (which I actually think is totally fucked, but there we are)
Anything which increases how much money is in the league will be good for the league, obviously. We can get that through the fans going to games, prize money or TV& Sponsorship money. This league has so much potential, though and just needs refurbishing. Imagine a world where those four teams I mentioned were CL regulars. Who would watch Man City vs Chelsea over a Milan vs Roma game? So much more prestige in that second tie.