With the response to my older post, I figured I should say that I finally killed this boss. I haven't been playing that group much, so they weren't higher level than when I was smashing my head against the brick wall, it was just a simple alteration of tactics. basically I followed the advice given earlier to approach Kelsereth from the left, so that when his minions run in, I can see them every step of the way and am ready with a Consecrate. Also followed the advice to bunch everyone up on the tank. Before, I had the DPS and healer spread in their usual three-abreast formation, so when someone was hit with the Ice Tomb, the others had to back up significantly to get it into LOS. This eventually scattered everyone, making it easier for them to pick up minions without realizing it, and generally sucked. When everyone's bunched right on the tank, I either don't have to move any toons at all or only have to tap the move-backward button to get the Ice Tomb in LOS and burn it down.

Of course, this is exactly as far as I can get in UK, but will try to push past when I get back to that team. Been working on some druids. I missed the Hillsbrad -> Desolace -> Tanaris -> Hinterlands -> WPL fun of old.