Reports on the official forums this morning are that those who completed the Dalaran orphan's quest (Oracle pet/Wolvar pet) last year are currently unable to start the quest again today. Blizzard has already chimed in with a response:

Aredek -- Children's Week not working
I'm terribly sorry about the delay in getting back to you all regarding this issue; however, this is an issue we are presently looking into. At this time, players who completed the Dalaran Children's Week quests will be unable to re-accept the quests. We hope to resolve this issue as soon as possible, but we do not have an ETA to provide at this time.

We will surely let you know as soon are more information becomes available.

Thank you all for your patience!

This annual reset glitch has happened a few times in the past with other seasonal events. This issue should not be affecting the Stormwind, Orgrimmar or Shattrath orphan quests. It should also not be affecting those who are doing the Dalaran orphan quest for the first time. More information about the current seasonal event can be found in our Children's Week guide updated for 2010.

We'll update this post when Blizzard announces the fix.

Update: Blizzard has announced that there is no fix this year:

Bashiok -- No fix for Children's Week this year
To clarify, this issue won't be able to be resolved for Children's Week this year. If you completed the quest previously you won't be able to complete it again for the other pet this year.

This article was originally published on WoW Insider.