The $30 Blizzard Cash Store Warforged Nightmare party mount.
You read that right: party mount. You can click on an item and get the mount for the duration of the instance/raid/BG/whatever.
But what they didn't tell you is that it combines the sparkle pony's ubiquity with the Lil' XT's mind boggling annoying sounds.
The noise was so bad from having about 13 of these at the starting gate in an Arathi Basin run that I turned my sound off. There was no way in hell I was going to click on the totem/whatever-it-is to get my own mount, and neither was a Mage.
"Get with the program!" one of the fellow Alliance BGers said.
"No thanks," I replied. "Blizz gets enough of my money, and I don't want to encourage them."
I could only imagine the obnoxious sounds of 13 metallic mounts clanking and steam whistling away. This isn't the "clink clink clink" of a Gnomish mount, but something right out of the Molten Core.*
I do have to hand it to Blizz in that they do give the people what they want --or at least they think they want-- but hearing this noise is almost too much.
*Not literally, but it sure does look like it could have come out of Blackrock.