I quite enjoyed this episode. I hadn't read any spoilers, so I was really wondering what was going on at the beginning - very creepy.
It was also great to see Connor Trinneer back in action. I enjoyed Enterprise, and it was great to see "Tripp" back on the screen, even if he was playing a wraith.
I'm a little disturbed at how easily he got away though - why didn't they have more security in place?
Very creepy that the wraith probably know all about Atlantis now, though.