Here's my experience with our first two 4e sessions with an actual persistant group. Not sure exactly what the point is and it's not particularly organized, but it's one group's experience:
Dragonborn Paladin of Bahamut, Maul, Plate
Halfling Brutal Scoundrel Rogue, Dagger, Shuriken, Hand X-bow, Leather
Human Cleric of the Raven Queen (ranged heal/buff focus), Mace, Chain
Eladrin Wizard (All attack powers AoE)
We purposely decided to test one of each role, since this "mini-campaign" is a dungeon crawl to get a feel for the combat system and rules. We've easily handled everything thrown at us.
We've fought about 6 or 7 combat encounters, haven't had anyone dropped once. Even though the wizard has nothing but AoEs, he's never dropped one on another player.
All our fights were against various versions of goblins + some rats at the end. In total, about 3/5 of the damage was done to the paladin, the wizard was hit once, no damage to the cleric, the rest was done to the rogue. Total damage done after two sessions was probably roughly even(maybe 10% variance) between all party members.
The first session and the first couple fights of the second, my paladin did a ton of damage(go maul!), but was barely on the charts the last two fights. In those last few fights, the wizard and cleric did a ton of damage. The rogue was the most consistant in damage output do to his high +to hit and decent attack rolls. We had some fights where the wizard, cleric, or paladin did a ton or almost no damage, but the rogue had pretty consistant damage from fight to fight.
Note: I recorded damage done, healing done, and damage taken for all the fights. In the first session, my format sucked and I missed a few things, but for the second session I have pretty solid numbers. We rolled damage against minions and I recorded it all as damage done, even though the minions took only one hp of it to die. The wizard and cleric's damage done totals go down considerably - and my paladin to a lesser degree - if you only count minions as 1 hp worth of damage.
In the first session, wizard had the lowest damage done and my paladin had the most. Second session was the opposite. My paladin got down to 3hp two or three times in one fight, but that was the closest we ever got to having someone go down. I don't think anyone stayed bloodied for more than one round. I don't think I ever worried that we might lose a fight, especially with our redundant cleric - paladin healing.
The fights were all xp balanced to slightly on the hard side(probably +100 xp or less) for 4 players. Having three classes with AoEs of some sort(Dragonbreath, Divine Glow, Wizard) makes a huge difference. With a few exceptions, minions were not an issue and we destroyed the two swarms we fought in about two rounds. Minions were often mostly dead from dragonbreath or divine glow before the wizard even got to go.
Divine mark rarely was useful since few things lived longer than a round or two after they were marked and they were attacking my paladin anyway. The one notable exception was when I had a dire rat pinned down with it, allowing the rogue and cleric to slip past with no OAs to take out a witch-doctor goblin. Maul + 2[W] or 3[W] was frickin' sweet. I think in those 6-7 fights, I only hit with my at-wills twice. I ended up doing alot of charges(which I almost always hit with - go figure) because my mobility was so low compared to the goblins we were fighting.
The rogue used mostly Sly Flourish ranged attacks so he could try to sneak and get combat advantage. With King's Castle usually only adding 1d4 to his damage, he rarely even bothered to use it. Used Positioning Strike once or twice, but I think the witch-doctor died from the hit so the effect didn't matter. Only in the last couple fights did he really spend much time in melee. In both he took more damage than my paladin as a result...
The cleric was a healing machine. Anyone bloodied was pretty much always healed(usually up to full or close) within a round. I only had to use lay on hands once in two days of game time. His divine glow accounted for probably 1/2 to 2/3 of his damage output. Raven-queen's blessing was a sweet extra bit of healing. In the second session, he beat the rogue and my paladin for damage done, only about 10-15 damage behind the wizard.
The wizard didn't do very well the first session, but in the second used his AoE arsenal to great effect - especially when he busted out the Flaming Sphere. If you don't think wizards have much battlefield control at low levels, watch a tactically played wizard play with a Flaming Sphere in a moderately-enclosed space. He did a fair share of minion sweeping, but also "softened up" tough foes before they got into melee, making them go down pretty quick once they got in.
I will re-affirm something I've seen mentioned on the boards: the cleric is a force multiplier. Any of the rest of us could probably be replaced with something else, but without a leader I think some of those easy encounters would have become brutal.
These fights did mostly take place in fairly narrow spaces, often with chokepoints that we exploited. I'm not sure how differently it might have gone if there was more maneuvering room and/or against other (non-goblin/rat foes). I imagine with more space my paladin mark would be to greater effect since tanking in many of these fights just meant standing in the middle of a narrow hallway or just charing in and being the closest to one the enemy. The rogue would probably be able to find Combat Advantage a bit more and the wizard and cleric might actually take some damage from stuff slipping around the sides.
The key thing is we felt like a party and everyone had moments where we got to do cool stuff. I was actually occasionally envious of all the healing the cleric got to do - and how well he did it. The rogue was fairly bland most of the time, doing moderate consistant damage, then he'd get combat advantage somehow and something usually died. The wizard probably had the most consistant damage(especially in the second session when he was rolling decent) since he was making an average of 2-3 attack rolls per AoE and hit more often than not.
So, anyways, huge ramble, but it's straight "from the trenches" with a combination of anecdotal and emperical evidence to back it up.
