Hi,
Appendix - maybe, but it would end up being pretty long :-)
CPAN - maybe, but I really don't think of PScheme as a "proper" language, its purpose is purely as a vehicle for discussing programming language concepts. Also, it's not really in the right namespace (Lang::PScheme would be better, but I'm too lazy to change all of that right now.) I'll certainly make tgz's available for each version from my site at some point, but the code is still somewhat in flux: I actually have separate CVS branches for each "version" and merge fixes/changes in one version upwards through each of the subsequent versions (so the diffs in the book remain sensible).
Tests - glad you approve :-) I recently ran v-0.0.9 through Devel::Cover and got something like 90% coverage without even trying, but that's mostly down to the recursive nature of the code.