I THOUGHT this is what Fourth Edition was going to do. I distinctly remember wizards of the coast saying something about the classes eating each other. Big fish>small fish. But then, this is coming from the same company that went on a massacre against it's forum members over what they perceived to be "leaks". Like they're the government, and have to protect top secret governments. Meanwhile not a month ago they were saying there was no Fourth Edition, keep buy Third Edition. Okay, maybe there IS Fourth Edition, but it's far off and still in development, okay, Fourth Edition is out in six months. Buy it all anyway. We're better then you...
The only thing WOTC did right, was giving some kind of classification for the classes. Like "striker, defender," etc. Categorizing them. Which of course, other mediums have done too, and better. I believe all classes, including prestige classes, should fall into one of these perceived kinds. But I'd expand it from the four presented in fourth edition...
Debuffer
Team Buffer
Tank/Self Buffer
Healer
Blaster
Utility
Summoner
That's seven classes. The players then get to level in one of the classes, and choose a base or prestige class ability that matches their classes respective field, or alternatively, can start selecting spells relative to their class type. Basically, the classes are kind of like the genetic class system of unearthed arcana. (In fact, this whole thing would probably be easier to do with the generic class sytem... but probably not as balanced) You can either advance your spellcasting ability one level as if you gained a sorcerer level, or gain a class ability. Here's an example;
Jim Profit wants to a debuffer. He must either decide to function as a level 1 sorcerer would's spell-list, (all must be debuff related spells) or he gains a class ability. I opt for class ability, and gain poison, the spell-like ability of the prestige class skin of acolyte. Using a fourth level spell, at first level 1/day may seem really terrible. But considering if I opted for the former, I'd be casting a lot more spells per day, and without that much difference. (Like say ray of enfeeblement) In fact, even if that poison 1/day was a supernatural ability, or was increased to 3/day. It would only be slightly better, as poison as a spell shouldn't of even been level four to begin with. It does not scale. And anyone with a few ranks in craft can make poison for cheap. So it'd probably be more optimal to take "poison use" as an ability, and just craft all the poisons I want. But all of them fit within the purviews of a debuffer.
I guess you could just do the same thing with all the spells lists throughout all the D&D books. Compose them, break them down into the seven categories of classes, make each one a class with their own proficiencies, hit dice, skillpoint, saving throw, and base attack bonus progression... and call it a day. But then, all the classes are essentially specialized sorcerers.
I don't know if I like the idea of a one class based system, as that's just mutants&masterminds. A decent system in it's own right. You can easily get D&D out of mutants&masterminds. Just imagine if D&D was a point based system, and used the toughness check variant if unearthed arcana.
However... I do like the class system, as I believe limitation is somewhat good to reduce cheese. Rather then me use debuffs specifically designed to ruin opponent's dexterity, so they cannot save against my fireball. I would have to invest so many levels in a debuffer and blaster class. Sure, I'd be good, but I wouldn't be GREAT. Mutants&Masterminds is a super hero campaign, and intended for over the top characters like Exalted. If you're looking for more of a dungeon crawling, solve puzzles, escape traps, and struggle with the enemy kind of adventure. That is not the direction you want to take it. I see Mutants&Masterminds more like Blue Dragon, Blue Dragon IS my favorite game technically. Because of how well it was designed all the way around. But flavor wise, I prefer Zelda. Even though they haven't changed Zelda in twenty six years, and could definitely afford too... I like the premise of Zelda of where you're not all powerful. Through cunning, the right magic items, and talent... THATS how you survive!!! (Ironically, it's Blue Dragon with the class system and Zelda is classless...)
It would be nice though to be able to make one of my ideas come true once in awhile, without having to bend the rules so much, or just outright ignore them. Like how I've wanted to make a dual wielding wand user for the longest time. Where he uses magic items as weapons. I don't want to be a spellcaster, I want to be an item-caster. But making items is so expensive. I don't need all the other crap. Like infusions of an artificer, or the spells per day of a caster, I just want to be able to make lots of magic items, use them, and then toss them. I actually had an idea for a fighter where he could craft magic items by just taking ranks in craft (wands), but the wands were so cheap, they negated the use of potions and scrolls. So in order for it to make sense, everything's market value would have to drop dramatically. I suppose I could make up some feat where I can reduce the gold price of a magic item. Like say...
Initial cost to make a wand: As normal. Just don't need a caster level or knowledge of the spell anymore.
"Craft Wands": Decrease gold price of wand by 10%. (Can take multiple times, but no more then 90%)
Want to take TWF so I can dual-wield wands obviously.
Level 20 Fighter: I'm dual-wielding wands of firestrom, CL 20.
(Regular price: 210,000. New price: 21,000.)
And it basically took all my feats to pull it off. Can't do it with potions or scrolls, though why would I need too? See... in Mutants&Masterminds, I could just take the power "Gadget" and essentially do the same thing. Gadget=If I want to be known for making items I don't plan to keep. Device=An item that defines me.
A flaw of my plan is that some classes would never get picked. Sure a healer and utility class might be useful, maybe even required... but who wants to get stuck being the band-aid or crazy shaman guy? Occasionally you might get lucky, but most players want to see some action. Also there's thin lines. Sometimes healing borders on buffing, and summoner, given the right summoning list... could fulfill any of the roles. Creating the same problems of the old system of an unfair advantage to certain classes. I would probably counter this by changing how each one does magic.
Summoner: Vancian magic. Prepared, limited spells per day. That ought to minimize munchkinism.
Healer: Spontaneous spells per day. Needs a limit so can't just keep spamming and keep everyone immortal.
Buff Others: Same as Healer, though not as necessary.
Self Buff: Skillcheck. Doesn't even need spells per day, as if fumbles, it costs him the round. Not a very good tank if you're constantly tripping over your own shoelaces.
Blaster: "Blood cost" (HP loss?) or the risk of fatigue. Basically, if you're going to be that good in combat. Destroying the big bad in one turn, you need to be your own worse enemy.
Debuff: Recharge magic. Five round downtime like with binders. Why??? To prevent spam.
Of course, this is all just speculation. I'm just trying to help.