I ran this a week and a half ago so I'm a little sketchy on the exact details but will try to reconstitute the battle. I just kind of hand waved past the first part of the role playing, explaining the situation and plopped them in front of the cave. I had five players and the paladin was left out. The first room was pretty much getting mopped up just as soon as the monsters were showing up. Each player took a minion out with their first action and the fighter moved to take out Ichi-ichi, though it took a couple turns. The next set of minions went down equally as fast to the range attackers, but their concentration was split by the other skirmisher and the slinger coming down. The wizard and cleric were close by when Varsuke came down while the ranger, fighter and warlock were going after the two kobolds. The skirmisher didn't last long but the slinger got a few shots off and started moving back to warn Meepo. Meanwhile, V came down and used the force lance to push the Cleric into the fire to nasty effect, but took a blast from the wizard. On his next turn V force blasted to knock the wizard a bit then headed back up the tunnel. The players took a brief break before moving on to reset encounter powers.
Here's where it got interesting though. During the break the more healthy players were scouting around a bit and when they decided to start moving again the ranger was heading down Meepo's tunnel while the wizard was towards the hobgoblin tunnel and they managed to get both enounters happening at once. The party mostly came to the aid of the ranger since they were closer that way anyway and the spider had all but dropped him in one hit. The wizard meanwhile had poked his head around to see what was up the tunnel V had come from and was narrowly missed by the readied archers. Readying his action, the wizard moved into the tunnel, dropped his daily in the middle of all of them then used an action point for the other area spell, nearly killing the two archers, wounding V and bringing the soldier right about the bloodied. Of course when the hobgoblins got to go, the wizard was quickly dropped. Still seriously impressed by his actions but I think he wasn't expecting the hobgoblins to be as tough as they were. The rest of the crew was cleaning up on Meepo and Ix and trying to get the ranger, now unconscious, fixed up. Meepo is actually a nasty little fighter with his cross bow quick shot and +11 to hit with the rapier. The spider and Meepo were trying to set up the fighter for flanking but moving past the fighter proved to be like a cheese grater in the narrow space. That fight got cleaned up but the hobgoblins were moving down the hall now. The players came through eventually but it was a rough fight, trying to take on both encounters. The hobs were softened up enough that they took up down without anyone else getting too messed up. With most dailies having been expended and everyone fairly beat up at this point, they decided to make an extended rest.
Which was interupted half way through by the return of the other raiding party. The ranger, needing only 4 hours as an eladrin was back up and went daily on the group and they were dispatched rather quickly. They settled back down for their last two hours for the rest of the group. After two hours, Nightscale was growing restless. Someone was in her cave and none of the minions had reported. The players wanted to get the last two hours in for the ranger to be back to full capacity, but the noises coming from up above let them know it might not be a good idea to hang around here much longer (if they had stayed Nightscale would have come down for them while they rested, I figured). They moved up the tunnel and found the lake, dragon pops out and breaths on them when a bunch are in range and it's on. Fighter crits her daily (ouch!) and the rest spread out to try and avoid the acid breath and drop range attacks. The fighter proved very resilient and the cleric was staying close enough to keep some healing going. They kept whittling away but some movement brought the wizard in range of a breath weapon (they had started to think about bailing when 120 points of damage hadn't yet brought the thing to bloodied!) and he caught the nasty brunt of it. Failed save after failed save against the recurring acid damage did him in for good. The ranger and warlock kept plinking away, the Cleric had critted his daily as well, giving him some extra damage with his lances. Eventually through sheer force of will and some fortunate rolls all around they managed to get Nightscale down far enough she decided it was time to get out of there. The bloodied immediate breathweapon very nearly did in the fighter. I know if I could have gotten her down the rest of the party would not have lasted long.
The rules were getting a little fast and loose towards the end of the night as it got later and I'm sure by very strictly sticking to them and using a little more tactical movement they probably would have been defeated all around by the dragon, but in the end they had a fight they just barely scraped by and felt they really had accomplished something. That's the whole point I think at the end of the day. It was a fun adventure for everyone and we may do some of the other adventures people have made up soon.
As far as 4e, our group has been playing for quite some time (we had very wide range of feeling about moving to 3e back in the day) but overall everyone seemed very positive about the change over to 4e (despite the first comment as the night began: "They switched Dex and Con?! I can't play this!"). We've migrated to a battle map over time anyway, using hexes mostly, as every encounter we had asked the DM to draw out maps anyway. We're all excited for June now (or even sooner for Keep on the Shadowfell).