The Dollhouse season 1 DVD (I love saying "season 1" and not "entire canceled series") will be shipping later this month, and it contains the never aired episode "Epitaph One."
It was produced for the DVD release to fulfill production commitments, and not originally intended to air on FOX, so no one has yet seen it (though it will get an airing at the upcoming Comic-Con). For the shows I care about, I've tried to avoid spoilers, but some of the particulars about "Epitaph One" have made their way into the geek infostream, and I've absorbed some (turn away now if you don't want to know ANYTHING about the episode) of the basics: the lovely and talented Felicia Day is a guest star, and the episode takes place in a somewhat dystopian future. Most of the regulars will appear in some fashion, and it was directed by Joss and written by Jed Whedon and Maurissa Tancharoen (from a story by Joss).
Today, a sneak peek found its way into the wild, and I have to say I'm.....intrigued. It doesn't give away much of the plot, but does provide a glimpse of a character that seems a little different from when we last saw them. Hmmmm. If you want to peep it for yourself, I think you can see it here.