Currently this is very much being overshadowed by the massive upgrade effort to Julia 0.7. I suspect that pushing this too hard before things have settled down a bit would be counterproductive.
As I’ve said, there shouldn’t be too much code involved in actually implementing this, the difficulty is in getting all the package maintainers on the same page. In principle I don’t even think that this would necessarily involve a separate package, though that may make it more difficult to get people to design uniform interfaces.
As for me my concrete plans are to create a common interface for JDBC.jl and LibPQ.jl (essentially PEP249) as this is something I will definitely need, but again this is overshadowed by the 0.7 transition for me, which has still yet to occur for the most critical code I use in my job. JDBC.jl and LibPQ.jl already have very similar interfaces, so again, this won’t involve very much actual code.