This morning I came across RaidBuffStatus. Update: I’ve since raid tested it and highly recommend this addon for raid leaders.
It provides intelligent raid buff checking prior to the pull, is talent-spec aware, has a real-time visual window of tank health/healer mana/dead healers/ missing buffs and (icing on the cake) has tank taunt warnings.
RaidBuffStatus also has an information video here, developed by a Finnish player (cool accent).
I like how seriously the author is differentiating himself from others; his documentation helps you choose RBS over alternatives.
Tank-taunt warnings: I actually don’t use an addon for this at the moment but thought I’d go get one, and was looking for an XRS replacement, which led me to RaidBuffStatus.
The alternative tank-taunt addons seem variously unmaintained. Tank Warnings hasn’t worked since 3.08 but the author recently commented he was updating it. OptiTaunt looks good but is slightly out of date too, albeit it probably still works.
Update June 12: I found two minor bugs, reported them via wowace tickets, and within 24 hours the developer had fixed them in r254. That’s brilliant.