No. Gosh people are being so stupid on this board. Why can't second place exist? A product selling better then one doesn't mean the end of the world to the other. Coke kills Pepsi, is Pepsi in trouble? Mcdonalds kills Wendy's, is Wendy's in trouble. Do this with every kind of product.
Developers will get to know the X1 better (some already said the new SKU helps a lot) and therefore create better games. I'm not saying the games will look better than on the PS4 but the difference won't be as big as many PS4 fanboys claim.