I'm curious whether you had the dragon use his darkness zone special ability. I did, and that really nerfed the casters and particularly nerfed the ranger. I thought this went against one of the design conceits of 4E wherein guys always had option, but sometimes had to take penalties.
Let me try to explain: In 3E, a knight can use a challenge ability to force enemies to attack him and only him. Conversely, in 4E, a paladin can use pain of death (or whatever it's called) to cause an enemy to take damage if he does not attack the pally. There's a difference there - the option to act and make a decision yet remains in 4E, but there are consequences.
I've got no problem with the dragon having a temporary darkness ability, or one that allowed attacks and line of sight albeit with a penalty. But the thick black veil just didn't do it for me.
That said, I have thoroughly enjoyed my two sessions of 4E and thank you (Olgar) for the great fan-made adventure. From my admittedly limited experience with 4E, I really get the feeling that 4E is "When DMs Strike Back" - as a DM, I have much more fun running NPCs and monsters than I did in 3E, and I enjoy the thoughts (hopes?) that I will not have to contend with godlike PCs once they hit 10th level and beyond.
Wis
p.s. Another thing I'm really hoping 4E accomplishes is to repudiate 3E's unfailing ability to marginalize certain characters classes as the party level increases. For example, there's little that magic cannot do - and do better - in mid- to high-levels of 3E. Want to scout a dungeon? Back, dastardly rogue with your +20 Move Sliently and +18 Hide - I'll simply cast arcane eye. The prevalence of spells that can fulfill every need, from scouting dungeons, to ruining a sense of mystery (I'm looking at you commune and find the path, to handing the limelight to NPCs (planar ally, anyone?) was troubling to say the least. Yes, yes - I know these things can be countered by a good DM with time on his hand, but dammit - it got old trying to write adventures under those types of themes. Yet I babble...forgive me.