I don't understand people complaining about a cross-gen title. It's a unique idea for consoles and if it works, people who own an X1 can immediately bank on a much larger player base, people that own a 360 might be influenced into buying an X1 after playing with their next-gen counterparts, the developer gets the assurance of their title getting released to the largest possible audience...
I mean I really don't see a downside.