I cleared Nidhogg on patch night. The fight is healing and dps check but its not impossible to pull off with i205 gear. Clearing it means everyone needs to respond to mechanics correctly and play their class to the best of their ability.
I am no Elitist or super human player, I do normal mode raiding. I have never set foot in savage mode and rarely touched the extreme modes, yet I cleared Nidhogg with a random group of people. As LunaFaye said if people start failing step in and say something point things out to people.