I found a nifty macro that will tell you if you have or have not killed a world boss in a given week. This comes in handy when you have more than one level capped character.
/run local z,t,s={[32099]='Sha of Anger this week.'},GetQuestsCompleted();for c,v in pairs(z) do if t[c] then s='' else s=' not' end print('You have'..s,'done',v) end
You have to put the name of the boss in the 'xxxxxx this week' field, but even still this macro is useful.