Also taking into account how serious both companies are and their previous positions in the market place I think this will end up being a fairly even match when things settle out. Software/operating system wise I think that both sides have pros and cons and that over time we will see things reach some form of feature parity. The Xbox will probably always have some more entertainment and casual features while the PS4 will probably always have a slight edge on the hardcore gaming features. But any killer app type stuff will probably be implemented by both sides over time. Over the years I'm sure both sides will also gain their own stable of must play exclusives. And this is the first generation where the hardware on both sides have been this similar, so cross platform titles should start to look very similar on both very quickly.
My personal preference is for the PS4.
My prediction is that the PS4 will win a. Umber of the first rounds but over time they will level out.