I just picked up The Trollfens expansion today and I liked how they had digital PDFs of all the rulebooks posted under the Support area of the website. Any idea when they will put this one up as well?

Same here, l have been looking for this since the expansion was released.

same, and also for the component into the Quest Vault

http://fantasyflightgames.com/ffg_content/descent-second-ed/support/DJ05_Rulebook.pdf

Looks like, besides some flavor text, and the specific rules regarding the Insight, Trap, Infection, and Weakened tokens (which together take up less than a page), it's pretty much the same as the other mini expansion. Though they did seem to add a symbol on the Secret Rooms tiles for where to place the Challenge Tokens.