As a big fan of Battletech games right from the Battletech: Crescent Hawks inception to the Mechwarrior Mercs series i would love the possibility of playing with mechs in a mmorpg universe.
Upgrading your base mech, exploring new areas. Doing missions with squads of guys. "Instances like in wow" could be full blown invasions of towns/cities. Commander section of the game where you can develop skills and trainignt o help fight. Maybe 2 or 3 factions fighting over a dynamic world.
Before my mind runs away with me....i am at work and have work to do. Mechs in a MMORPG would be a dream. What other games would you guys love to see one day?