Heh, they get ripped either way. When they updated Naxx for level 80 people were ripping them for removing the old dungeon.

I don't know how well it would work (and I know that they would be ripped for "rehashing content") but it'd be nice to see an heroic version of MC some day. Or to really think crazy, imagine heroic MC where the bosses and abilities are the same but just scaled for new levels, and "super-extra heroic with chili on top" MC where the bosses had new abilities and maybe new adds.

They certainly don't make them like MC anymore, though. MC was, for the most part, a pretty small and pretty open dungeon with a high trash density. Now they're much more compartmentalized and linear. Same with dungeons.