I think SE team made a great effort to give us some fun on the fools day. I miss the unicorns, the bacon as a payment, and the holiday hats, and it is a pity that all that stuff will just live in our memories, and eventually get lost for ever and ever.
And here comes the question: Is there any place where we can access to any sort of archive of this stuff (with limited functionality, or just as a image gallery, I don't know) once they are gone?
If not, It would be nice to create it, so that work (the hats in Christmas, this of the unicoins, etc) could be better honored. Something like what Google does with the doodles.