Ryan, one thing to consider is paid downloads of the lessons on iTunes. Anyone who complains just needs to try a little harder and download them for free from viddler.
But at $1.95-$4.95/lesson or $0.99-$1.95 for a play along, could be convenient for iPad/iPhone/PC users who want a permenant copy. I can esp see the playalongs being useful to have on the iPad.
Cheaper and simpler distribution than DVDs. Also more convenient for most users who don't need to rip the DVD now.
Personally, I wouldn't pay since I can download and convert any videos that I want (but don't because I don't have the energy)...but for people who prefer the convenience, I think they would be willing to pay a few dollars.
Edit: Perhaps you have done this already....I can't quite remember.