For Activision's sake- hell, for gaming in general! -I hope this moron's advice goes ignored. The first game to impliment this is going to see one of two things:
1) Horrifically low sales numbers if it's not a AAA-title.
2) A mind-numbingly high return rate if it is, as kids learn Mommy and Daddy aren't going to shell out monthly for an extra subscription for a single game's sake. At some point, the costs far outweigh the benefit.
Besides, why the hell would you think paying extra for an FPS would be worth a damn? Are the developers going to add new maps for free? New weapons? New playmodes? At least with an MMO, you have a consistently progressing world. Always there, always moving, always thriving and changing. Well, if the MMO doesn't suck, anyway, but I digress.
One thing this moron is REALLY not getting as well is the culture gap. Let me explain; 360 owners? If they play online, they've already accepted the idea of subscription fees. It's a hard sell to convince them to pay more on top, but not impossible. PS3 owners? Oh good gravy no. How many of them picked the PS3 BECAUSE there's no subscription fee for online play? I know several myself and I've seen others on here. Worse still, you'd basically be asking the average PS3 gamer to change their whole outlook on the cost-value of the game... while other studios could be offering online multiplayer free of charge. Guess where the gamers would go then?
The ONLY thing that made any sense was the idea of pay-to-play tournaments. THAT might work. And it MIGHT keep the game from being a massive flop. Anything else would require a lot, including making a title people would want to buy, content strong enough to make people want to subscribe, and in the case of cross-platform games or PS3 exclusives, you'd have to completely change the culture perception on pay-to-play costs... which it's probably too late to do to that extent.