The plugin manager is designed to provide an in browser interface to administrators to install modules and themes. It automates the process of downloading a project release, extracting files from it and installing them in their appropriate locations.
6.x-1.x is the currently supported version. In order to catch back up, the order that I'll be targeting issues is bug, refactor, feature request, task.
At some point or another everyone decides to "rewrite from scratch." It almost never turns out properly. This was my attempt. I'm back to 1.x now...