v1.0 is the official release, meaning that we've completed all production efforts and addressed testing feedback. Both of these will be handled via the ticket system in Sourceforge. Tickets are arranged by milestone so we can assess which areas of the game require more attention. Additionally, each ticket can be assigned to a Sourceforge user - that provides us accountability for our volunteer pool.
This system is a combination of the system you suggested and the innate working of the Sourceforge ticket system. Since we're using an open-source concept, anyone can submit work for the game. For those of us who are committed to regular work on the game, we can search by milestone or tag. Sorting tickets by the milestone should be straightforward. Tags are implemented during ticket creation and include "creative", "scripting", "animation", "sprite", "GUI", "bugs", and "view". Just perform a search using a tag and you'll receive the grouping you prefer. Anyone who desires can lead ticket resolution for any section available.
Also, I'm posting tickets as I encounter issues, but anyone should be able to submit a ticket. Currently, I'm only compiling tickets for Room Scripts, but I've set milestones for Spells, Dialogs, and the Combat System.
So, by all means, let's focus on one section at a time, but I think it's important that we have a system in place that provides for casual contributions as well. Eventually, we'll need a system for receiving feedback from play testers. This information system should support both needs while maintaining consistency for the primary development members.
P.S. I noticed that you're adding tickets while I'm writing this. Thanks for that!