We are using pgAdmin a lot for day to day database development and support. JSON is increasingly important to us as the features in 9.3/9.4 make this a dream for DB development.
Editing json fields in pgAdmin is almost unworkable (Mac OSX) and we think that a better option would be to shell out to an external editor. This would make life a lot easier not only for data editing but also for stored procedure development.
Is this on the roadmap at all? If not my company may be willing to do the work if we are pointed at the best way to achieve it.
AFAIK, not at all. But, actually, pgAdmin doesn't seem the best tool to edit data.