Couple of improvements in the Plugins directory and associated procedures are just being planned and it's the right time to discuss them now.
It's evident we need to improve the approval procedures for the new plugins. The queue of submitted plugins awaiting for the initial review became pretty long (45 plugins right now) and it's current top priority for the plugins facilitators team to deal with it. We believe it would help if more validation checks are executed automatically. Reported issues can then be fixed by the plugins authors promptly. It's not rare that the acceptance review takes longer just because the newly registered plugin does not have the basic meta-information filled (description, documentation links, source code management URL etc). We currently work on some UI improvements so that maintainers are warned and asked to fix these formal aspects of the registration prior to actual human review of the plugin code.
There is a plan to implement these validators (that include checks for the coding style, strings files syntax required by AMOS, code plagiarism etc) so that they can be executed separately from the plugin registration. In other words, the plugin author should have a chance to execute all these checks even before they actually submit their plugin to the directory.
We would also like to give the developers community a chance to participate on plugins reviews and testing. In some sort of peer-assessment spirit. Peer-reviews are generally very good for learning and reflection (developers seem to spot mistakes in other's work more easily than in their own work). We all learn well by looking at other's work and comparing it with our own. And it would provide the authors with richer feedback if their plugin was checked by multiple peers.
Some sort of integration with crowd-funding and Moodle jobs offering databases would be nice to have. It might help the plugins authors to collect funding for their work.
We also plan improvements in the UI for maintainers of existing plugins. One of the first things I would like to see soon is a mechanism that allows to easily release a new version of the plugin after it has been tagged in the external source code management system like Github. The directory already supports it partially, thanks to the cool repository plugin by Dan Poltawski (in the file picker, you can fetch the ZIP directly from Github without the need to download and upload it). We plan to extend this further so that releasing a new version in our directory is just a matter of a button click (or two).