Oh yes, I did. I totally did.
Other Gray Box now has a sequel.
Grab it at
http://www.psychsoftware.org/digital.html
Official first-party youtube video is also up-
http://www.youtube.com/watch?v=n3sHYGYhV2Y
but I intentionally omitted the final-final-post-final easter-egg ;)
(Warning: contains Portal 2 spoiler-esque content. If you haven't played Portal 2, go beat Portal 2. Unless you haven't played Portal, in which case go beat Portal, then watch Other Gray Box, THEN beat Portal 2. Then watch this.)