I submitted a similar idea as a last second YC application.
Basic points of differentiation were that it would be fully extensible (add/remove any input fields), and that it would have a killer API.
The API would allow you to submit issues from anywhere you please: you could write a plugin for Eclipse (or favorite IDE) or you could widgetize it into a js include file so people could submit issues directly from your web page (think beta testers).
We use Subversion, so each developer has a local copy of the code on their machine. They also each have a copy of the database and table structure. What is the best way to manage changes in the database/table structure so that each developer is using the latest db version?
Have you checked out Code Igniter? It is a php framework that implements the MVC design pattern. Forcing the seperation of the different layers makes things much "prettier" in my opinion.