TwinBahamut,
I was going to respond inline, but this was easier.
I disagree with both your claims. While certainly roles were not "designed-in" in early MMOs like Everquest, they became part of the design of later ones. WoW designers, for instance, discuss them pretty openly when talking about the design of the game.
A similar point applies to aggro. In EQ it may have just been an AI limitation, but later games (including both WoW and Guild Wars) have added mechanics very similar to marking that explicitly interact with the aggro system. Taunt-type mechanics have been popular for a while.
I think you miss the important point that, while both concepts flow from somewhat naturally from what came before, it was in the context of MMOs that they were a) popularized and b) became intentional game design elements. Thus, even if they're not strictly completely new in some sense, they (or at least their use as intentional design elements) are associated with MMOs in people's minds. And that's what matters.
You are, of course, correct that I'm only discussing MMOs. But then, 99% of the "4e is videogame-y!!" threads I've seen boil down to comparing it to MMOs. I don't think I've ever seen an (explained) comparison of it to console RPGs, or even single player computer RPGs.
Regarding the MMO class roles and aggro, these were first openly discussed in various MUDs in the mid to early '90s. SO to say they were "popularised" by MMO's such as WOW and EQ, shows a distinct lack appreciation of the history of games.
To take it further back, "roles" are built into all rpg systems, all the way back to OD&D the classic fighter, cleric, mage, thief build of parties, each character bringing a seperate set of abilities to the group. CRPGs took a look at this concept early on in thier history and built on it to help players build on a character that would fit thier playing style. The 4e designers took note of this and used it during thier design process.
Looking further back, even wargames, which lead to the development of RPG's, have "roles" for units (Heavy infantry, skirmishers, artillery, leadership and others).
As far as RPG's in general using elements from Computer Games, particularly CRPGs, it is something I am in favour of. If something works in one medium and can be simulated or incorporated in another in a way that improves the second, then it is a good thing.
Take for example being more transparent about class designs and roles, it helps focus the designers and players when looking at a class and evaluating it's abilities. A fighter might not dish out the raw damage of a rogue or ranger, but that is not his role, his role is to get the monsters and npc's to focus on him during a combat and allow his striker partners to move around the battlefield to get into advantageous positions and dish out damage. Abilities like combat challenge and combat superiority most likely flowed from designating a role to each class to help them fulfill thier roles.
As another example, the designers looked at possible aggro mechanics ealy on in the design phase, found that it didn't work in the pen and paper format and scrapped the idea.
So yes, properly implemented, video game influence is a good and awesome thing. Same for cribbing ideas from cardgames, boardgames and wargames as well as other rpg systems.
Phaezen