It's been no secret that Activision has been looking to get some kind of subscription fee out of players for a couple of years now, so this Elite pass looks like as close as they can get without totally alienating the market.
Gears of War 3 has obviously introduced the Season Pass, but with that they've been quite clear that it gets you a discount compared to if you had bought each piece of DLC separate. It's fairly smart in that obviously you might not even be playing the game anymore by the time the DLC is all released an so wouldn't have bothered to buy it.
So far it looks like with COD Elite that they are trying to make a subscription desirable by releasing content every month. If the map packs are the usual sort of price of £10 in points, then that's pretty rotten to pay that outright every month. Clearly this will span over all the future COD games, so they can keep you on a continuing subscription.
The real question though is as to whether they are holding back features and content so that without a subscription, you are going to get less of an experience.