@Hyde and I are currently working through a second set of ten videos, which we're hoping to have done in a month or so. As I'm sure you'll appreciate, it takes quite a bit of time to put these together (writing, recording and editing), so it's a slow program. We currently have slots allocated for around 50 videos, although that will take many years to finish (and will likely be continually expanded).
As GWAS said, we're also looking into getting an interactive page up and running on the site, but at the moment that's proving technically quite difficult and we don't really have enough videos to justify all the effort... yet!
Glad you like them though, it's good to hear that they're well received.