I noticed with the release of the JSON API that it should be very possible now to not have the entire git repo stored locally for every person. It means that people will only need to keep, essentially, a list of every package name, which could be checked for freshness using an ETAG rather than a git pull. Installs will just require a HTTP request for a given package name. To me, it seems to make a lot more sense.
Is this the plan for the future? Is there something like this in the works?