Thanks to an excellent alt run my guild organized, I now have the famous Storming the Citadel achievement all those pickup raids are asking for. That is 4 out of 12 bosses in Icecrown Citadel killed, and two attempts on Festergut before we called it a night. Very nice result. And apart from the first boss not too much running around during the fights, so I could concentrate on playing my class. Given that I was one of only 2 healers, that was challenging enough for me.
Besides the fun, I got a Mag'hari Chieftain's Staff, and the ring for having reached friendly reputation with the Ashen Verdict. So quite a successful evening!