Let's see what ingredients it has/needs to be a successful sport.
Game - a fun and competitive game that people play on all levels, requires a lot of skill, and is interesting to watch. This is why basketball and soccer are so popular.
Fans - while the majority of TL is male, it appears that Korean fans are predominantly female. No real sport has more female fans than male ones. What happened to all the male Korean gamers that used to follow the pro scene in 2002?
Structure - Currently Starcraft is structured in an interesting way in that it's an 1v1 (with some 2v2) sport but is also divided up into teams. Yet it's not a true team sport in that teams don't have hometowns and their own stadiums. In terms of professional Starcraft, perhaps the most similar real sport is tennis. Both are individual sports, one-on-one matches, and there are multiple tournaments throughout year hosted by different groups. Yet tennis is not nearly as successful as team sports.
Teams - For the professional scene to really take off, I think there needs to be more parity between the different countries so people actually have someone to root for. Each pro team will need a hometown associated with them so that people will cheer for them. Of course this implies that the game needs to be much more popular than it is now.
So here's the problem. The most popular sports are team sports, but Starcraft is conducive to 1v1. Teams can never really take off unless team leagues take precedence over individual leagues. Or they figure out how to make 5v5 SC balanced and viable (team melee perhaps?).
This hybrid individual/team structure has no precedent in actual sports. I'm not saying its impossible for e-sports to be much more popular, but it'll be difficult for Starcraft with it's current structure.
As for other games, I think those such as Tribes/Battlefield or even WoW PvP have much more potential if they only ever made a game fun/competitive/balanced/popular enough. I think Blizzard's next game should be a team-based FPS.