Isn't this the way it always used to be done... not counting expansion packs from RTS's, I remember Sonic and Knuckles pretty much contained most of Sonic 3 and Sonic 2 in it and merely just completed the puzzle when you plugged them together... you also need another genesis game to unlock Blue Spheres as well. I would assume any possibility of addons back then would have had to work the same way.
Sure its not so necessary with the distribution of DLC, but I don't think this is an entirely new way to rip gamers off. And I'm sure that they haven't completely left full functionality in there, just enough that it'll only take a bit of DLC to complete it.
Now I know the psychology isn't "well we are paying less because it isn't unlocked", but I think it really should be. I wish I could buy Megaman 10 for eight dollars and not play as Protoman until I can afford it. Games you pay for the title and license, not for what you get... as I stated in more detail in my previous post.