Several of my colleagues have already reported this. But players no longer need a key to get into Karazhan. What you do need is 1 player with a key to let everyone in. The concept is similar to that of Arcatraz.
As Eyonix said:
It’s not a matter of difficulty, really. We wanted to make it more alt friendly at this point. I’ve gotten my kara key on four characters, and have helped a dozen others. I’m really quite content with never having to work on the attunement quest for kara again. Also, you should note that at least one person in the raid will need the Master’s Key, as the gate will function much like Arcatraz or Shattered Halls.
What about them noobs?
My stance on this is that you’re responsible for the raid group you’re joining. If you’re leading it and don’t agree with having an undergeared player with the group, then you can just remove them from the raid. Karazhan isn’t as hard as it used to be when TBC first came out. A lot of the trash in the instance got removed. A lot of players understand how the fights work now. I wouldn’t be surprised to see players on their 5th alt running Karazhan (I’m on my 3rd).
I suppose the argument here is similar to that of noobs going into Black Temple. So what if they can get into Karazhan and BT and such? It doesn’t mean they’re going to succeed most of the time. And if they happen to be holding back your raid group, you have the right to remove them. If I get pickups who are interested in joining my group, I typically screen their gear and their spec first before saying yes or no. A simple check before hand can save many heartaches later.
It seems to me that there are some players out there who are too darn nice and don’t know how to uninvite someone from a party or a group. All that needs to happen is for the raid leader to right click their name and uninvite. Voila!