We are getting together a preliminary Naxxramas raid on Feb 29th at 7 pm. You will have to be attuned for it. If you are not exalted with Argent Dawn, it will cost you some gold.
More information: http://www.wowwiki.com/Naxxramas
Colter is leading the raid.
I will post more information as it develops.
So, why run Nax? Well, many people in this server have not run the larger instances. There is a good chance that with the next expansion, this version of Nax will be changed. It appears that the citadel will be moving to Northrend.
Although it is designed for 40 level 60 people, it has been run with 20-25 level 70's. I suspect it will be difficult to get a full group of 40 people. So, if you are in your 60's, you are welcome to come. The more the merrier.
-Khronos