I know where UnderDaGun is coming from, but I think it wasn't THAT bad - sure, there were a few builds that were basically unstoppable, but if you did anything else, it was a challenge for awhile (almost any setup was a runaway effect if you lived long enough). I'd say there were more interesting builds than "broken" ones.
MoM2 would be tough for anyone to do at this point - it's been so long that the opinions of how to do it will be contentious (just look at the UFO:AM/UFO:AS games and how some X-Com fans react - and those don't even claim to be true sequels, just in the same genre).
But, it would definitely be neat to see StarDock do *some* kind of strat game in a fantasy setting, whether or not they get the MoM rights. A lot of what's been done is directly applicable; the biggest change I can imagine is that they'd either have to dumb down the tactical combat to use the GalCiv style, or they'd have to develop a more hands-on combat model (perferably the TBS model that MoM had).
The problem is, as UnderDaGun hints, is that what was great about MoM is in some ways what would be so terrible about a sequel. The lack of balance would have to be fixed, but the overpowered heroes and spellcasting in combat was actually part of what was fun (IMHO). So you'd have to strike a very fine balance between having heroes that were fun and made a difference but weren't overpowered.
Actually, has anyone else tried the NEW demo for HoMM5? That's actually got a lot of the old MoM elements - the grid-style turn-based combat, heroes, etc. It doesn't have the "central wizard" factor so much, but otherwise it's very much like MoM, writ 3-D. What it's missing is the "world-map" sized play (at least, from what the demo showed), which is what I liked about MoM; if the map is too small, it tends to come down to surviving long enough to build a superarmy that can crush anything in it's path, one big battle to wipe out each other player's main army, and game over.