"Update: We are aware of the issue that is currently affecting the Children’s Week quest line in Dalaran which does not allow players who have completed the quest line last year to take part in it again this year. We do not currently have a fix planned to address this issue at this point in time." - Aredek
"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." - Bashiok
translation: we probably won't be fixing this issue this time around. i say "probably" because i still have some hope (however small and weak it may be) that blizzard will pull a bunny out of a magic hat and fix the northrend children's week quest chain. extending the in-game event due to this devastating bug would also be a plus...
it's quite disappointing that there seems to be a lack of attention and TLC for this year's children's week bug. many other in-game events that have had similar bumps and hurdles were tackled and fixed with such fervor. yet it is apparent from the blue post's comments addressing this issue, that blizzard has "better" things to do at the moment.
i suppose i can't blame them considering the alpha testing for cataclysm is now out, a starcraft 2 date has been released, AND they still have yet to announce a blizzcon 2010 ticket sale date. blizzard has quite a bit on their plate at the moment, so one little (big?) bug in-game will probably be last on their 'to-do' list.
still... this is very disappointing news for collectors.