Check your raid comp
As you probably know by now, buffs and debuffs are changing significantly in patch 3.0.2, which is expected to hit next Tuesday, October 14. Most buffs that are only provided by one class are going to be provided by several, mana return from Shadow Priests is getting nerfed and spread out, you won't be able to stack Heroism/Bloodlust the same way, and so on. In general Blizz's goal was to make raid formation less about stacking the right classes, and more about bringing friends and good players.
However, all the new buffs and debuffs can make a raid leader's head spin, in case they do decide they want to organize a raid so as to optimize buff coverage (and surely some raid leaders will want to do that). Fortunately, MMO-Champion has made an outstanding web tool to help you figure out your raid composition. Just drag-and-drop specs into the raid groups, and check the right-hand column to see what buffs and debuffs you'll get.
It will also tell you whether you have the best buff in a given category; in my sample raid comp (my last Karazhan run), for instance, we only have Battle Shout, which is not as good of an AP buff as Blessing of Might. If you're missing a buff and want to see how you could get it, just mouse-over the buff, and it'll tell you what classes bring it. The one thing I really wish this tool had that it doesn't is a corresponding ability for specs: mouse over the spec and it'll tell you what buffs they bring. Overall though, this is really useful; I'm not a min-maxing raid leader (or a raid leader at all, actually), but I'm probably going to make use of it just to check what my raids and groups be getting. And because it's really cool.
