1. Interview Darl McBride and ask him what his deal is.
2. Interview rms on any number of subjects.
3. When a version of Unity or Gnome shell comes out, do a quick video demo of it followed by comments from someone on the dev team explaining the rationale, and also someone who hates it venting about how much it sucks.
4. Interview former senator Dodd about the future of copyright
5. Interview some scientists about the Higgs boson.
6. Interview Sergei Brin about privacy.
7. Robots fighting.
8. Bruce Schneier about TSA
These are all things that would be interesting, but for the most part video is not the appropriate format. For everything except 1 and 3 a transcript is a much better idea, it's faster, it's easier to skip the fluff and get to the good part, and Google can find it for future reference. For 3 a transcript with screenshots is going to be quite sufficient. 7 actually merits a video.