I was up all night hacking on autodafe, and it was glorious.
I have nailed down the solution - with tests - for the only problem which was really worrying me, which was transforming libtool commands into invocations of your local compiler/linker and getting a sane result.
This means that I'm not many days away from a 1.0 release. To give it a serious test, a friend and I will be pair-programming the transition of a large, old, complex project in mid-May.