We started the WC a few weeks back. It's been tough, but no character deaths so far.
Highlights:
The swarms were pretty nasty. Fortunately, the party took a break between the two and had a chance to refill their oil supply.
Lucky (is there any other kind?) crits on both the owl bear and the mad slasher.
Not so lucky with the traps. I don't think they've deactivated a single one. Set off the sarcophagus trap twice.
Alastor's horrific gaze hit the same character twice. Got it the first time when the party first encountered Alastor. Found his bones, buried them, but then came back before tracking down the rest of the family. Alastor got pissy and hit 'em again.
This group's notorious for setting off multiple encounters. They encountered the bombadier beetle in the nap room, then at the tail end of that battle ran across the intersection and stirred up the second swarm and beetle. Just after they finished both battles, they set fire to the hive which contained the old corpses. One member ran down the hall where he had seen water during the previous battle. Seeing as how he wa all alone, the water elemental attacked. A crit took care of it, but it could have been much worse.
Again with the multiple encounters: when they first got to Alastor's haunt, the rogue crawled along the beam searching for traps. His search check found the trigger in the beam, so I had Alastor warn him. The party starts talking with Alastor and finds out about his bones, etc. In the process, Alastor gets angry and irrational (he's a teenager, after all) and uses malevolence to take over the rogue. The fighter (who's the rogue's cousin) starts angrily searching for Alastor's bones to calm him down and get him to release the rogue when - you guessed it - the grick makes its listen check. So the ranger's dancing around the beam trying to shoot the grick and not set off the trap, the fighter (who had been hit by the horrific gaze earlier) is taking a beating from the grick, the possessed rogue is running all over the balls making jokes and teasing the cleric who's trying to hit the rogue with a spell to let him make a second save (can't remember the name of the spell) Of course, the rogue is the only member of the party with a magic weapon, so no one can nick the grick...it got a little dicey there for a while.