InTheBuff : WoWInterface Downloads : WotLK Beta (it's also available on Curse and through WoWMatrix.)
InTheBuff helps WotLK raidleaders come to grips with the new buff/debuff system.
It scans through your raidmembers, looking at their talent specs, and then brings up a window showing you what buffs are covered by whom and what buffs your raid doesn't have.
Buffs/debuffs can be moused over, and you will see who provides them currently, and what classes/specs are capable of providing it. It tells you how many were OOR or offline and who they were.
Furthermore, where applicable, abilities are classified as weak or strong. For example: basic CoE is +10% magic damage, and is weak (yellow.) Maledictioned CoE, Earth and Moon, and Ebon Plaguebringer are all 13%, so they are strong (green.)
It checks everything other than Hunter pets, and can be adjusted to scan only a portion of the raid: only the first 25, the first 10, or just by groups: 1-2, 3-4, etc. if you are forming up multiple 10-mans in the same raid.
Features I'm planning to add include hunter pets, and also text and graphical views of just the missing/imperfect buffs: right now the full view is a bit unwieldy if pulls are going on at the same time, for example, and not being able to report it means all raid organizers would need to run the mod.
Here's a scan in the middle of Malygos (the /itb raid10 command wasn't working at that point, to just scan groups 1-2; it is now, however.)
Many thanks to Slake of Advent Fury for his excellent code in his rewrite of Scrub (much of which I used, with his permission) and his invaluable help in writing this.