Moxie can already show tasks in a timeline as a gantt chart, so why not projects? I would like to have a bird's-eye view of the projects on a timeline to better grasp of the upcoming projects, dues dates, etc.

Other ideas:

If a projects timeline can also display any milestones coming up that would be a big bonus too. Maybe connecting it to the invoice payment plan, so the next payments could be utilized as markers on the timeline view of the project.