What's so cool about it? They're the exact same eggs you've been picking up that whole time, except that you can set them out. You can loot them right away for an added chance of whatever loot may be in them, but I'm not sure why you'd do that, except for possibly completing Dressed for the Occasion/Sunday's Finest. What makes it better is that other people can loot them.
What makes that so great? If you can get an organized crew (and their alts) together, you can set up your own Noblegarden Hunt for your guild or your friends and family. Laying an egg has a 1 hour cooldown, so each of you will only be able to set out one egg each, but with a sizable group that might not be too terrible. A brief hunt, but you can make it exciting! Feralas, perhaps? Icecrown? The interior of a cleared Ulduar? Just take it far, far away from busy cities or hubs. You don't want to lay an egg out in the Stormwind Trade District. Joe McMullet will loot that thing in a flash, and that's no good.
I don't know for sure how long the eggs stick around, but it seems a fairly long time. I managed to set one up in Darnassus and it was there for at least 45 minutes before a nude level 1 Druidess named Sxxybabby ground it to dust beneath her haphazardly-thrusting hips of feral fury. Hence my suggestion that you take your hunt away from major cities. Very far away.
I'll be honest here, though. The one hour cooldown on these is pretty lame and sort of limits the size of what you can coordinate. I'd love for Blizzard to hotfix the eggs to have no cooldown, or a much shorter cooldown. Being able to throw our own egg hunts (in an easier way than rotating alts to get 10 eggs down) would add a lot of extra flavor this this event, rather than it just being an egg (and achievement) grind for a day then forgotten forever. Drop the cooldown, and expand upon the concept for future holidays. This could be good stuff.