"do you think they are going to make the games on each system separately and not port the games from xbox to ps4"
There isn't a snowballs chance in hell of them EVER making the games for each system seperately because it would at least triple the time/effort/work required to develop a game.
I highly doubt that Activision will break their business partnership with Xbox, especially with the way they have completely screwed other platforms over the years (which caused many to abandon their platform of choice to switch to Xbox) Not to mention Microsoft has alot more money to tempt Activision with than Sony does, and as anyone knows the ONLY thing Activision cares about is making as much money possible with the least amount of time/effort spent.
My prediction: Unless the next-gen Xbox console is a complete disaster, CoD (along with many other titles) will continue to be made primarly for Xbox and ported to other platforms for many years to come. (which is unfortunate as Xbox is the worst platform IMO)
They only have and exclusive deal for dlc and the only reason they made them on xbox was because sony software was hard to build on and the easy route was to port from xbox,now games can be made on pc systems and ported to systems thanks to next gen tech.And activision is on board with the ps4 which was stated from the sony conference recently
"activision is on board with the ps4"
Activision hasn´t any deals with sony there are not even rumors to find in the the net so this is all wish thinking.
Finally it´s not about the developing it´s about the money and that´s where every companie´s wound spot is. Many people are yet upset because they think that not much will be changed to the gaming developing´s landscape so I guess we should wait.
In the end sony and ms will built a new console with a better hardware then now, all those words and promises they make sound good but it´s all franchise for their own product I´m excited what will be left if the clouds of promises clear and reality shows its true face