I mentioned this elsewhere, but this was the very first riff I ever requested, about 2 years before I became an active, regular poster.
I'm kinda disappointed that it was Blame Society doing it as a Rifftrax Presents. Outside of a Star Wars context, a Darth Vader impersonator just seems weird. It's like Santa Claus. In December, he's a symbol of the season; caring, giving, joy, yadda yadda. In August... he's just a fat man with a beard who's dress inappropriately for the weather.
I haven't actually viewed the 'trax yet. I only got halfway done (ripped the DVD, downloaded the riff file, fabricated part of the menus) before I had to go to work today. I expect I'll watch tommorrow.