You can go back and get the gems for your 'key' to UBRS now, they drop every single time, but even now you don't need it. If I remember right it was part of the content that got thrown out when they remover Onyxia attunement.

You remembered wrong, I organized a Leeeeeeeeeroy! run last week and left my key in the bank. I had to hearth and fly back with it.

The only reason they removed attunement for Onyxia is the alliance quest chain was impossible to complete after the King returned. I could easily be wrong, but I believe the eventual goal is to rework the quest chain so it is still in game...but that may never happen. I believe MC and BWL still have their attunements if you don't want to go in through BRD or UBRS respectively.

It is nice that they are opening this up. Though I soloed LBRS the other night just to get the key for UBRS. I was disappointed, however, when I found that I needed three people to continue through UBRS even though I had the key. I was able to get a couple of guildies to come in to do the ritual, so it wasn't a complete stopper, but it was a bit of a pain.

Anyways, I was able to complete the requirements for the keys and attunments needed for BWL and MC with a minimal amount of help, in just a few hours, and I'm hopping I can recruit a few people to run these-- mostly because I've never had a chance to see them, I started playing 3 or 4 months after BC started. Kudos to blizzard for opening them up.

no, they got rid of all the old raid attunements for good