I just ran my party through that tonight. I even warned them ahead of time about this encounter and how people were complaining online, tpks, etc. I even told them it was level six. I never do this, but we wanted to see how it would play because we're trying out 4e and this product. I gave them an extended rest for free after taking out the outside people. So, they went in knowing it was level six, that it had tpked several groups, and they were fully rested/refreshed. Party was minotaur fighter, githyanki star pact warlock, githyanki rogue, elf ranger, and dwarf cleric. All of them burned all their dailies and encounters. They all used their action points and second winds. Result: fighter and rogue dead, all three others bloodied, and they barely pulled of a victory. If I had not told them about the encounter ahead of time it most likely would have been a tpk and I'm sure they would have never wanted me to DM again, in fact, they confirmed this. Oh, and they managed to take out the first wave entirely in three rounds before the second wave was able to engage. Which didn't make sense anyway, because at one point the wyrmpriest and dragonshields would have been able to see the PCs only at only a dozen or so squares away. But we wanted to play it as written, so they hung back until the end of the third round. Oh, and some of the PCs got a surprise round on the first wave as well. 1st level party + 6th level encounter = bad design.