Heres some of my videos on the 3 new raid instances in WOTLK:

My Favorite so far, Malygos from the Eye of Eternity:
http://www.youtube.com/watch?v=IXIvR1eprv8
(We didn't kill him - just reached the last phase before he enraged - still an AMAZING fight)

Sartharion The Onyx Guardian from The Obsidian Sanctum:
http://www.youtube.com/watch?v=XjLYGIu5f6c
(This is with all 3 helper-dragons down, which makes it really easy)

And a couple Naxx Bosses:
Loatheb - http://www.youtube.com/watch?v=8aNcXyC0FF4
Noth the Plaguebringer - http://www.youtube.com/watch?v=kq_SZuJrHKo
Anub'Rekhan - http://www.youtube.com/watch?v=l0HzpdaXCcQ
Heigan the Unclean - http://www.youtube.com/watch?v=wISpfy69QMc
And of course the GARGOYLE BOSS - http://www.youtube.com/watch?v=Q1k8ZR-yqyI