There won't be a KOTOR 3, at least not from BioWare/Obsidian. BioWare is making The Knights of the Old Republic into an MMORPG like World of WarCraft, like you suggested. I'm not into that either.
I just thought that once you paid for a game, then you just play to your heart's content. But with these MMORPGs it wants to pay more to keep playing the game you bought. I mean, I never liked that.
I wouldn't mind playing for a game if it was a good one and they kept adding new and interesting levels or missions. I've been happy to pay for the Half-Life 2 episodes. The problem with MMORPG's, IMHO, is that they force you to do meaningless crap to get experience to level up. How running around in a forest killing giant spiders for hours makes you a better adventurer I have no clue.