Sounds like the same capitalism mindset that makes the U.S. tick... why so bent out of shape over it? I don't agree with what they did, but I can't blame them for trying something to get money for the maps they put time and money into developing and play testing. You aren't FORCED to buy a map pack at all, and I hate when people claim such a stupid thing.
Ordinarily I'd agree with you, and in fact, I'm not mad they pulled this, just disappointed. I understand it's in their best interests, but it's decidedly against mine. So, I'm voting with my wallet. I'm not buying the game, and if they pull this shit in the future, I won't buy it then either. I've been following battlefield: Bad company 2 as long as I was following MW2, and from what I can see, BC2 is shaping up to be a FAR better game than MW2. So, in march, I'll buy that. And I'll also participate in the PC beta next month, and I'll ALSO be able to see how I like the close to final product when they offer a *GASP* DEMO of the game in jan/feb.
Can't wait.
On your other point, I can easily see how they could provide DLC and force you to buy it. Wanna join MP? What if it keeps sending you to games where the map is one you don't have? Or, even worse, requires you to update in order to even join MP? I don't know if this will come to pass, but it sure seems like it will, and if it does, you have a bricked game that you paid $60 for to only have SP. Hopefully it won't happen, but with IWnet, they decide whether it happens or not. You no longer have a say.