Thanks everyone for your feedback. It gives a sense of what contributions would be welcome. There seems no clear consensus that there is anything on my list that is drop-dead important. There doesn't seem much desire to move beyond the current build system; while interesting, I'm not getting a strong sense that people would actually use a package management system (unless "if you build it, they will come"); textinfo and a length manual seem sufficient to people, although there is some desire to update look and feel. Overall these are big projects that I'm not sure would be accepted by guile maintainers.
I think I might work on the least controversial, and the one that Ludo seemed interested in - de-icing of ice-9 modules and other namespaces towards more semantically meaningful identifiers. How about I draw up a proposal and post it to this list? -- Chad