Well remember that M&M is not a "normal" d20 game... so they changed lots of stuff (in a REALLY good way if you ask me). NOW for a 196 pg. book all the rules that you need are in the game, the art is great and it looks really nice. Just a quick overview of stuff off the top of my head...
Super-Strength does not add to your to-hit bonus for HtH combat
Super-Dexterity does not add to your to-hit bonus for Ranged combat
There is no "Armor Class" bonus for armor. You have a Defense score which you can define any way you want, and Armor (and Protection and Force Field) lower the amount of damage an attack does.
There are no other dice required but a d20.
Instead of Hit Points you have a Damage Save.
There are no classes.
You still have levels but they don't really mean the same thing they do in D&D, they are
Power Levels and determine how many points you have
No AoO
Attributes are the same but Max out at a score of 20, anything above that is Super-Human. Skills and Feats are mostly the same as D&D but to fit this system.
Over on the Green Ronin boards there are a couple of people running different games in all kinds of different settings. I know of at least two who are working on fantasy stuff and there their are some Pulpy games (lower power level). They seem to think it works great for this.
I totally love this game BTW, I think it is really the best Supers game out right now (I gave up on Hero a while ago, and while I still really like Deeds Not Words and SaS, M&M is just so much better for me...and me alone

)