If the corrupt assets is the problem, how do I unlink them when I can't access the project?
Unfortunately I didn't enable auto-save,
You know, there is these cute Save as Copy and Save Incremental thingies in the menu.... I mean, if I had worked on this for that long and it were that critical, I sure as hell would have a project_00.aep up to project_20.aep on my drives, possibly more iterations, and I'd back them up each and every day to an external drive or USB stick at least. Anyway, if you think it depends on teh footage, the proper thing to do is to offline the footage by moving it to another place. You can always reload and relink it later. That also includes trying to open the project on another system. If that doesn't work, then indeed you may be FUBARd...
Fortunately, I figued a way to fix it. I've been using premiere along with AE, so I tried opening a previous save from the premiere project (auto-save was enabled), this seemed to do the trick, I had to re-link all the asset files in premiere, it took a while but it worked. If I were to guess the problem would be a asset linking from AE to Premiere was bad, I'm not sure though.
Lesson learned; enable auto-save.
As Mylenium suggests, periodically using the Increment & Save command is a good way to protect against such failures. It's better than auto-save for this purpose because you can save at specific milestones and---even more important---the new versions don't end up overwriting the old versions as is true with auto-save, which only keeps a specified number of versions.