WoW Insider posted recently about the removal of engineering pet and cooking stove combo Pierre from patch 5.2. We weren't sure why he'd gone, but in more bad news for engineers, the Sky Claw mount is also absent, as Ghostcrawler confirms below:
@blehninja It's not. We had to pull it at the last second. Hopefully we can fix it and it will return.- Greg Street (@Ghostcrawler) March 6, 2013
It's always a shame when much-anticipated items can't make it into the game, especially when they're as cool as the Sky Claw. We hope for their speedy repair, and to see them soon.