I use a wiki for strawman feature proposals and for the roadmap; each entry in the roadmap gets a bug in Bugzilla, and all milestones/releases get a tracking bug depending on the bugs that should go in. milestones/releases are every six months, so there's an inherent deadline in there.

it's an open source project, so this not only helps me having a clear idea of what I'm meant to be doing, but it also helps others to contribute to it, by giving a precise idea of what can be worked on at any given time.