Well i'm hoping to get Ghosts for the Xbox One today, yes i already bought it on another system but i just got my XB1 yesterday. Besides I wouldn't think the current numbers is about as high as they can go because majority of people are still on XB360 and PS3 atm so gradually over the year people will upgrade therefore meaning possible more sales of ghosts on the XB1. There is also other countries that XB1 hasn't released in yet so overall I think numbers will go up a bit as the year progresses.
That seems logical..but can one define the exact point in time when people will start to come over to the next gen? Not really, the way I see it, is that people can upgrade at any time, there's always new machines being bought every week and month. I see your point that it will take time to rebuild the player base which was created on the XB360 and PS3 but consoles are always being sold every month which is why I think numbers will gradually increase over the year. Maybe not massively but...theres still a chance. Besides whatever the player count is currently that's still plenty to find and play games through online multiplayer. It's not like any modes have 0 players, there is a large enough community to account for all the modes. Sure it's even better to have numbers like the last gen consoles but it's not like we desperately NEED players. Whenever they come, that's cool. ^_^
I somewhat disagree with the current number being fine. In most playlists, at least the more popular ones, the number is perfectly fine, but in less popular ones like hunted heavy duty and some hardcore modes you are stuck in the same lobby playing with the same people. In my opinion, I think 100k+ would be ideal.