Thank for your reply Ben.
Just for my own knowledge, what stops developers from being able to do this?
Is it an internal cost for development or do you have pay royalties or licencing fees to MS and Sony?
Or is it as most suggest, Sony is just selective of what games they allow it to happen for?
I guess once the Playstation Network is hosted by MS data centers, that will remove some of the barriers.
Multiple things. It's more complex if your MP wasn't setup with this in mind. I won't go into the whole first party element.