I found this on Curse.com and here is the link:
BuffBroker - Addons - Curse
What does it do?
It should really be called Potluck Planner. You're going to a party, and can only bring one dish; what should you bring? Joanne can cook pretty much everything, and her Mac & Cheese is amazing; but Frank can ONLY make Mac & Cheese, so she should probably bring something else. Chuck can bring BBQ chicken or pork, and both are really good; not everyone there will eat pork though. This makes your life hard. Ideally, you'll find out what everyone else is bringing, and cook up something unique and appropriate to the situation. That's boring, tedious, and rarely happens.
In Warcraft, the party is a dungeon/heroic/raid, and the food is buffs. Buff Broker looks at the talents of your party, the spells they can cast, the spells they HAVE cast, and the spells they can't cast anymore (mutually exclusive shouts, etc). It profiles the role of each party member, and what buffs that role wants (in order of important). It basically does a bunch of information gathering and math, automatically, before coming up with suggestions for each individual, class, or raid. Each time you click the main button, it performs the next best suggestion (cast <spell> on target/class/raid). It even handles single, class-wide, and raid-wide conflicts (ie: lesser buffs on hybrids).