According to the minutes from their last board meeting they are indeed creating an interface with Disc Golf Scene. To what extent that interface will give DGS exclusive status with the PDGA for online registration is not mentioned. I love DGS and think they do a great job, however, I don't think the PDGA should give one vendor exclusive priority and allow for competition among the various online registration services.
The October minutes also talk about bringing online registration in-house. I'm not sure how good an idea that is based on the current state of the web site.
Source:
http://www.pdga.com/board-minutes