Mercifully for those of us occupied with a big day of family events and chocolate this Easter, the Noblegarden holiday doesn't appear to have changed from its vastly improved form in 2009. No changes appeared on any of the PTRs over the past year, and as far as we're aware, there hasn't been any data-mined information on new items or bosses.
Noblegarden will run this year from Sunday, April 4 (this Sunday) through Sunday, April 11. If you've never done Noblegarden before or only done its fairly low-key, pre-2009 version, it helps to know that Noble Gardener (the holiday's meta) is part of the year-long What A Long, Strange Trip It's Been achievement that rewards the 310% speed Violet Proto-Drake.
What I've done here is collected our resources on Noblegarden into one easily navigable guide, updated and clarified where necessary, and also added some frequently asked questions that we received during last year's holiday. If you have any other questions, please drop them in the comments below, and I'll make sure they get answered. As with all WoW holidays, we'll be around as they go live to make sure any updates or changes are covered here!