They only have 2 options in this case, from a legal stand point. They can either honor the contracts already in place and let the games be released on multiple platforms. Or they can try to buy Sony out of the contract. But considering the monetary value, I don't see Sony being willing to let them buy them out. The capital that the sales would create is more than Microsoft could afford, as they would have to try to match that, or Sony could sue them for lost/stolen profits. At least they could in some courts. The laws here in the states change from zip code to zip code so much, that I just can't keep up with it.