Genre identity

There has be a push in recent years to integrate multiple types of gameplay into single video games.  Sometimes, this has been done to great effect:  Metroid Prime is one of the pinnacles of the previous generation of gaming, and it has one of the best mixture of FPS and platforming gameplay done yet to date.  Castlevania games took up experience points and equippable weapons from RPGs to great effect with Symphony of the Night and haven't looked back since.

How much of this is too much until we lose a sense of what a game's genre is?  For instance, considering the recent Team Fortress 2 patch to utilize a backpack to hold a limited amount of equippable items, how much longer will it remain more FPS than MMORPG?  Will we eventually be running Goldrush in the same way that Ragnarok Online players run the Clock Tower and Mandragoras to grind levels and items?  With each new patch of equipment mods, it seems that the barrier to entry becomes higher and higher -- a trait identified with World of Warcraft, not Call of Duty.