I did the GenCon pick-up as well. I don't remember exactly how it was worded, but I was under the impression that my pre-order would give me a permanent copy of the 6th case.
Instead, I just got a link to an electronic version of the 6th case that went down after GenCon was over. I saw no way to download the files from the site either.
Since I didn't have time to play the 6th case during GenCon (I was volunteering 8+ hours a day), I feel kind of cheated out of the "promise" of the 6th case with a pre-order.
Is there anyway I can still get access to the 6th case?
Access to Case 6 was not a part of the Gen Con Pickup Offer. Only the 6th character was. Case 6 was available for the limited time for all of the Gen Con attendees (without the download option), as it is the convention case (it was also a part of the original pre-order).
Case 6 will be available on various other events and in the FLGSs.