Let's say that vanilla Naxx and wotlk Naxx never existed, this raid releases tomorrow and it only has one difficulty, it releases tomorrow, how long would it take for the first guild to kill KT.
Obviously it'd be a little hard to properly introduce many of the mechanics today but let's assume it's as pure of a copy as possible in terms of difficulty.
Some things are still a factor: resist gear, consumables, Patchwerk etc are scaled to require the same high amount of dps relatively to current dps.
I imagine it wouldn't take very long but I'd like to read opinions.