"Games running alongside each other" probably means that Terran, Zerg and Protoss games can all play against each other in multiplayer. I doubt there'll be a limitation of Terran only plays Terran units, Zerg only plays Zerg units - you get the point. That does not sound like Blizzard at all.

What they might charge more for is more of the single player story. That makes sense - making a campaign takes time, especially campaign who keep up with the Blizzard name. Cinematics, voice talents etc - I'm not sure if it's right to charge 60$ for more single player missions, maybe less would be more appropriate here (and we don't know either way), but I can understand charging for the future content. It isn't simply a map-pack.

Finally, you have NO idea what you're talking about, and are simply jumping to conclusions. Your-higher-deity-of-choice knows how you got voted Insightful.