I've been thinking about this for a little while now, but i'm not sure what to do with it. No reason to put it on blizz's forums cuz there is no way in hell they'll do something that demands work. Hopefully you'll like it ^^
A Caverns of time // Opera event like instance, located in CoT ofc.
It is an arena oriented PvE instance, meaning that 25-people will enter the instance, and be ported into a specially made arena for this event, where you'll meet a random boss from the old days (like ragnaros, baron geddon, chromaggus, maexna, u get the idea).
You can meet 3 bosses a week, all 3 are random and you'll get saved the minute to enter the instance (there is NO trash). The first one you meet is EASY, 2nd is MEDIUM, 3rd is HARD. You can meet all the bosses on each difficulty, the only difference in regards to the difficuly is the hp, dmg or perhaps something special about a phase, who cares, who knows.
If you beat the boss, you get a chest with some epax in it. Domo style.
The idea is that you get to revisit old content, i'd like to fight against some of da ol' foo's again.
Feedback wanted ;D
Edit1: Regarding details of how hard the bosses will be or how good the epics will be: i have no idea. I'm merely presenting the concept :P