No doubt there will be problems to start with but hopefully it'll make the game less frustrating once teething problems are fixed.
I also think it depends where the servers are based. Will people from Europe have servers based in Europe? Or will they just be based in the US?
I'm definitely happy about this new. I'm getting Ghosts first on the 360 and then on the PS4 when I get one. It's nice to know I'll get servers for both platforms.