The roller-coaster of "will they or won't they remove the Ulduar raid drake rewards" seems to have come to a definitive answer. The rusted and ironbound proto-drakes will be removed, but they will give us "about 1 month of warning" so you can make a final push if you really want it. The drakes are rewards for completing Glory of the Ulduar Raider (and the 25-man version).
Bornakk points out the parallel with the Arena mount rewards, and says that this is no accident: these are supposed to be rewards for the "top tier" of raiders, and letting people earn them with more powerful equipment from higher raids would defeat that purpose. Therefore, he says we should expect it to go this way in the future, as it was with the Naxx drakes.
As a side note, he says they may be removed when patch 3.2 comes out or some time after. This suggests to me that they think there's a decent chance patch 3.2 will come out less than a month from now. If they knew it was going to come out later, they'd just give the one month warning a month before they expected the patch to drop.
Patch 3.2 will bring about a new 5, 10, and 25 man instance to WoW, and usher in a new 40-man battleground called the Isle of Conquest. WoW.com will have you covered every step of the way, from extensive PTR coverage through the official live release. Check out WoW.com's Guide to Patch 3.2 for all the latest!