the German-speaking Wikipedia decided in  that the MediaViewer should be opt-in instead of opt-out for logged-in- and anonymous-users. To make it clear: We do NOT demand a complete deactivation of the MediaViewer, everybody who is willing to help to improve the MediaViewer should be able to do it. We just request to change the default from has-to-opt-out to can-opt-in.
Because the WMF-guys told us that most WMF-techs are away at the moment, the dewp-community is OK with giving you time until
- A u g u s t 2014 to make the change.
Thanks in advantage :-).