Webdoc 11: "Becoming Obi-Wan" has some ESB footage, but it's ripped directly from the DVDs (at least I think it is). The same goes for Webdoc 16: "Going to the Dark Side" & Webdoc 17: "Endlessly Compelling". Have a look through those if you can.
Interestingly, there isn't that much BTS stuff in these webdocs, and if there is ever any footage taken directly from the OT films, it's usuall Star Wars or Return of the Jedi. ESB gets left out a bit.
Can anyone clear this up: the press release says that the Episode III DVD will include the 15-part web-documentary series. There are 20 installments. I hope this is just an oversight in the details as I know I'd feel ripped off if not all 20 parts were included on the DVD. I'm sure they will be though.