The current plan is to completely kill svn by turning off the svn server and viewvc and such. But that's pretty heavy-handed, and we'd like to do a trial run to break anything we missed. Seems like this should be doable with a setting or hook which makes all the svn repos readable only by people in a specific list (e.g. the list of folks who can modify locked_paths).

See how feasible this is, and develop a plan to do so.