The Noblegarden events have returned and are live today! Druidic festivities are taking place across Azeroth today through next Sunday! There will be an egg hunt, new treats and prizes found in the rare eggs, Chocolate Currency, and an all new achievement!
Here's the official Noblegarden notice from WorldofWarcraft.com:

The Noblegarden event is returning to Azeroth with some new additions. Players can take part in the druidic festivities spreading ‘round all corners of the map all week beginning Sunday, April 26, and ending Sunday, May 3. Features include:

• Noblegarden egg hunt and daily quests located in starting towns such as Goldshire, Razor Hill, Kharanos, and Brill
• All-new Noblegarden treats and prizes found rarely in eggs
• Chocolate as a currency! (Or just indulge your sweet tooth)
• All new achievements found in the World Events tab

Please join us in celebrating this annual event like never before. Whether you celebrate Noblegarden in a traditional manner or you have a longing for sweet chocolates and festive garments, we hope you’re able to come together and give yourself a break from competing in cutthroat Arena battles or laying siege to Ulduar.

Its origins steeped in druidic festivals from times long past, the current incarnation of Noblegarden is a contrast between ancient traditions and modern interpretations. While some races of Azeroth try to stay true to the original spirit of the holiday, others prefer a more lighthearted approach -- in essence, looking everywhere for festively decorated eggs and collecting the goodies found therein. One tenet all can agree on is that the feast of Noblegarden is meant to bring communities together to share the joy of life and friendship.

Features I Want a Noblegarden Egg!
The egg hunt is on! The towns of Azeroth and their immediate environs have been liberally sprinkled with Noblegarden eggs for players to collect in a ravenous frenzy -- er, in the spirit of sharing. These eggs contain treats fit for commoners and kings alike -- mostly, they contain delicious Noblegarden chocolate.

Every so often, a Noblegarden egg will contain something besides chocolate, as a variety of special items are also hidden inside. These special items include seasonal clothing, special prizes, and more. However, if you're not fortunate enough to find the prize you want, you can still purchase them from special vendors located in towns. The currency for these prizes? Noblegarden chocolate, of course!

Achievements and Daily Quests
New achievements have been added for Noblegarden and can be seen in the World Events section in the Achievements interface. In addition, a new daily quest is offered from Noblegarden questgivers located in towns.