MM9 is fine if you're so starved for MM action that you just can't help yourself.
I followed 3DO pretty closely around MM7. Basically, they spread out a lot of resources making Crusaders of Might and Magic (a mediocre linear action RPG), the Heroes series, and a failed MMO which later begat Legends of Might and Magic (an attempt at a Counter Strike-style online fragfest).
It's a wonder MM9 got made at all. It's clear that the designers didn't quite no how to adapt the epic style of the MM series to the technically limited engine they were using. The first enemies you fight are tiny skeleton men who are laughably ugly. The zones are tiny and the inventory system is headache inducing.
However, after I played it for a few hours and got over the look and mistakes. It wasn't too bad of an RPG.
Dark Messiah of Might and Magic comes from a different development team altogether and has nothing to do with the Might and Magic universe. However, it's a fun action RPG. It's designed so that you can use the environment to your advantage while fighting. For example, you can kick enemies into walls of spikes, you can lay a patch of ice down and watch them slide off of cliffs. There are quite a few things to enjoy.
DoMM has almost no "world" to it. In the beginning there's a city, but you never shop or complete side quests, etc. The voice acting is also pretty cheesy.
I don't know if we'll ever see an official Might and Magic10. Video gaming has changed. The multiple-character, first-person RPG genre is dead. With true 3D games, we expect to see our characters in the world and interact with them. In that regard, Bioware kind of killed a lot of the traditional RPG franchises that depended on that gimmick.
You can also blame MMOs. For a while, every company had one in the works. The money was too good. As the games failed again and again, resources became scattered. Teams dissolved. When I think of all the MMOs that never got published or failed, I have to think that those teams could have cranked out pretty solid RPGs instead.
If it was up to me, I'd go old school and remake Might and Magic. It would follow the MM8 set-up and have you create one character and meet others along the way. Also like MM8, you'd move in first-person without your other characters "existing" in the world. There WOULD be inter-character dialogue and actions as well. But who knows what, if any, we'll ever get in the way of a true MM RPG.