I doubt that drivethrurpg.com will be around a year from now.
First off, the pricing is ridiculous. An entire level of the distribution system is gone. It's now vendor->retailer->consumer, cutting out the distribution channel. That should eliminate about 30% of the cover price. The second thing that needs to be factored into PDF pricing is print production costs; not the cost of 1 unit when the publisher prints 1,000+ at a time, but the cost for the consumer to print the book out and store it in an organized fashion (be it a binder or taking it to kino's for output). At the very least, that's another $4 knocked off the price. Given the ridiculous prices, entities involved on the vendor or retailer tiers are being greedy. The existence of some low cost PDFs on the site suggest that it is the vendors.
Second, it looks like no one bothered explaining to the vendors exactly how easy it is to break the DRM of PDF files. Adobe has been pushing their DRM crap for more than 5 years now. If it worked, it would be commonplace by now. But to give you an idea how easy it is, for me, it is a simple process involving 5 clicks of the mouse, nothing more. If any DriveThruRPG vendor wants more details, they can email me and ask.
Third, consumers don't like DRM. They're restricted in copy'n'paste (10 times in 10 days) and I've heard some complaints about printing issues (DRM interferes with PS output to printers using Adobe's own drivers). Consumers can't keep a copy at home on the desktop they use for internet services and their laptops, because each time you open the file on the other computer, you have to get permission to read it. You upgrade your memory, add a new hard drive, change the processor, and you need to get permissions again. How many times do you think a consumer will tolerate that overly intrusive nonsense before they abandon a game system anyway?
I hope vendors are paying attention to the VAST negative feedback that has developed in the last 48 hours. There are literally hundreds of negative posts on the subject on rpg.net. I have no doubt that we'll see a drastic rise in the number of posts in coming weeks.