EDIT: Whoa whoa whoa, I seem to have missed the boat by about two months. My bad. Uh, should I just start a new thread somewhere?
/EDIT
Everyone who's against this idea seems to think John is suggesting that the game actually gets easy. He's not. He's suggesting that the fight changes depending on the group's skill level, preventing frustrating and time-consuming wipes. It's a basic sketch that needs fleshing out and tweaking to be effective.
To take his idea a step further, you could incorporate lore into this system. Let's say you're fighting a boss who, according to his backstory, is full of himself, haughty, and just an all-around cocky butthead. He starts out not giving his all because he expects you to die quickly. If you really start hammering it on him (i.e. you dip his health to a certain point in a certain amount of time), he'll pull out all the stops and gain access to brutal attacks that he wouldn't use on a team that is only slowly gaining the upper hand, and thus not using the most optimal strategy/setup. Only the elite players would get to face the strongest version of the boss, while those who don't feel like training/farming/finding the right guild could still win. They would be fighting an inferior version of the boss, but they could get past it.
It's not like the boss would be easy for them, though. This guy would be a challenge for anyone. They would likely wipe a few times before they learned what to do or implemented the strategy correctly. They would also lose access to a few pieces of gear. Let's say this guy realizes he's really getting his butt handed to him, so he traps you in the room with a few waves of henchmen while he grabs his big guns. If you kill him while he's wearing this gear, it's all yours, along with access to that secret room full of treasure that he so graciously revealed when he went to power up.
Meanwhile, you can still come back later and wail on the boss for whatever reason. He has a cap of how hard he can get, and if you have the right loot or level, you'll mop the floor with him.
Also, the system doesn't have to be so strongly scaled for every boss. The Lich King would still be tough as nails from the get-go, but if you beat the other bosses in his dungeon without making them go all-out on you, he wouldn't be AS hard. He would still take a lot of tries and adequate strategy, but it would be possible for lesser-geared people to take him down. Again, the rewards wouldn't be nearly as great, and the loot level gap between his forms would be higher than a lower-tier boss. Let's say you're showing Arthas what you're really made of. He calls upon his true power and puts everything he has into his gear, buffing it permanently. If you kill him, you get better versions of his drops. Maybe you get a vastly better version of his ring, or a special trinket that he summoned just to deal with you.
As for the issue of Blizzard losing money, they could actually gain revenue this way. A lot of players feel shut out by the grinding requirement and just don't play after a certain point, leaving their accounts to rot. If they got a taste of the end-game and hear that with the right stuff it can get better, a good portion of them would likely come back and grind their way to a more difficult, and rewarding, experience. The end result of this is not only player hours gained from people actually completing the game all the way through (by doing a minimal amount of grinding), but additional player hours gained from those same people doing it all over again the hard way.
A few points that are just a tad off topic:
Personally, I really, really don't have time to play WoW all day to meet an arbitrary requirement for beating a boss (especially when that requirement is gear), and the time sink required to pass later dungeons is one of the reasons I quit altogether. I'm sure I'm not alone. When you boil it down to the amount of money Blizz is making for subscriptions, as the majority of posters here seem to be doing, grabbing new gear is just a micro-transaction. And the luck aspect of it is something that really puts me off. It feels like gambling. "Want these gauntlets? That'll cost you anywhere from $0.35 to $7.00, depending on how generous the drop system is and whether or not your guildies hog all the drops."
Also, for a moment, imagine the system did get implemented: If you're so hardcore about your gaming experience, be hardcore about it and play a little Iron Man. In the event that your healer dies and the boss is set up to go easier on you from that point on, let the boss wipe you and try it again. You DO have a choice in the matter, you know.
