I've updated http://gcc.gnu.org/wiki/tuples to show the items we still have to go through. To avoid stepping on each other's toes, please claim the items you are working (or plan to work on) in the list.
I've arranged the items in the plan to reflect the critical path that should take us to bootstrap C on our desktops. If you notice anything missing please add it to the list. I've marked the major milestones in bold. Thanks.