Earlier quoted context omitted.
Speaking of, I think I'm speaking at CUSEC this year I sure hope you're speaking given that they just today announced it on the website http://2010.cusec.net/11-20/thomas-ptacek-security-researche... =) All the advice I can give you is be honest and be yourself. CUSEC has always been very informal compared to most other conferences, more of a discussion between students and people they respect more than anything else…
I figured the room might be a bit too generalist to want to hear 40-50 minutes of crypto flaws, and so I was thinking about wrapping the crypto stuff up in a talk that made a technical case in favor of DRM. If people tell me real-world crypto is going to keep people in their seats, though, I'm totally down for that; it's a much easier talk.
I don't feel very comfortable giving advice about the direction of your talk; I can only speak for myself. If you have questions I highly recommend you ask the director of presentations. That said, personally I think the case in favor of DRM could be quite interesting since I've never heard a technical person argue in that direction. (At least not while doing more than simply assuming the token devil's advocate role.) If you make a good case you'll definitely get lots of questions/objections after!