Yay, now we can go Mining with friends! How awesome would it be if we could drive the Mako with three people? One drives, one shoots and one...navigates? Reloads the main gun? Whatever.
Seriously though, I'm pretty skeptical about all this. Mass Effect has always been intended to be a singleplayer game, suddenly adding CO-OP in the third installment seems rather unnecessary to me. I think Yahtzee once said that good storytelling and CO-OP don't mix well in the same way that a book isn't designed to be read by two people.
According to the article BioWare realizes this, and goes with some side missions that are playable in CO-OP. That should work, hence they are giving this CO-OP feature for free, because there is no way in hell that I (and a lot of others I imagine) are going to pay for a couple of side missions that I can play with others that have zero revelance to the plot.
Please, BioWare. I'm begging you, instead of wasting your time and money on these useless features, spend it on the singleplayer!