OP: Congrats!
I, too share the joy of a fresh LK kill on the precipice of Cataclysm.
After many months of trying and failing with different people, I had a group of my most trusted friends blaze our way through ICC, despite a few hiccups on BQL and Sindragosa. We tried for 2 full days of pulls, and were met with repair bills. I finally told them that if they really don't want Kingslayer they should just walk away. The next pull, everything went as smooth as it could have ever been. Defile placement was perfect, Valk kills were quick, and Frostmourne only managed to get 1 person. Vent erupted when he killed us all via Frostmourne (signaling the end of the fight/rp/kill phase). It was a mixed blessing as I had gotten the kill on my druid healer alt as opposed to my warrior main, but I was elated that all my friends whom have worked just as hard as myself to get the elusive LK kill, and thusly, Kingslayer.
As they say, better late than not at all!