I found it! The website is:
http://www.evilleagueofevil.com/ And they'll likely have this page change soon after Comic Con this weekend!
The general idea (as Joss told us and as
I posted here)is for you to make ELoE application videos no longer than 3 minutes, and the best ten will be on the "Doctor Horrible's Sing-Along Blog" DVD.
Oh! And there's a hidden email! Bad Horse's no less!
(Hint: Highlight his name.)
EDIT:
I emailed Bad Horse, and Bad Horse emailed me! XD
The Evil League of Evil soon will be accepting applications for membership. Please stand by.
-- Bad Horse
P.S. Please forgive the absence of song. The Bad Horse Chorus currently is recovering from a Horrible hang-over.
Begs the question...how does Bad Horse type? XD