I was thinking of cataclysm raids and seeing the picture of the orge dude (name?) that isnt chogal in bastion of twilight raid; and i thought of a cool boss idea ( at least i like it ).
For the fight, the boss would insti-kill anyone who he hit no matter fricken what. Adds would be constantly pooring into the room at the same rate from start to end. He would be immune to all damange (or at least massive redux) unless the DPS are mounted, read on. Every ~30-45 seconds he would use his massive weapon and strike at everything infront of him giving you about 2 seconds to get free of the kill zone. After striking the ground his weapon becomes stuck for 10 seconds giving ample time for some DPS (im thinking one in 10 man, 3 in 25) to "mount" the boss and do full out DPS at 100% damage increase to his one and only weak spot. After a DPS has mounted they would get a debuff that wouldnt allow them to remount the boss until it wore off.
Now for the rest of the fight, the tank(s) would be managing adds, healers healing, and DPS would also have to follow a strict kill order and manage CC's during the entire fight. every time the the DPS drops off the boss two things happen; the boss ignores 20% of any speed reductions ( after he reaches 100% reduction he begins to move 20% faster to form an enrage timer) and the adds would enrage, making them immune to CC and dealing massive damage.
Ok, some of you may picked on what im saying here in terms of managing the boss and not getting WTF pwned by him; you kite. Better speaking. One or two of the DPS kites him.
I think something like this could be an interesting fight for cata; it includes CC, kill orders, kiting and raid mechanics that aren't in game (as far as i know).
/discuss
PS: +10 internets if you can figure out the reference of "little" people climbing onto an ugly giant things back.