Knowing Activision, Destiny will be marketed to high heavens, and then rammed down our throats every 1-2 years. The MMO aspect of it seems cool though. Unfortunately, the last publisher to try an MMOFPS was Sony, and we all know how that turned out. Destiny won't flop, but it probably won't take COD's place as Activision's flagship franchise. On a side note, in the Bungie-Activision deal, Activision is supposed to publish four Destiny games.
As for Titanfall, EA will inevitably market this as YET ANOTHER attempt to take down Call of Duty. It didn't happen with Bulletstorm, Bad Company 2, or Medal of Honor, so it won't happen here. The lack of a real campaign will hurt the game, and it's not releasing on PlayStation systems.
With that said, Destiny will be bigger. Unless Titanfall is a runaway hit, I see it fading into obscurity in 5 years, after a sequel.
