I wrote up an overview of possible CodeWorld projects for Summer of Code at
https://github.com/haskell-org/summer-of-haskell/blob/master/content/ideas/codeworld.md One thing that would make the list more persuasive is a longer list of potential mentors. If you'd be interested in being a mentor for Summer of Code this year, let me know and I can add you to that list. More people on that list makes the organization look more promising to students, and to Google (which still haven't made final decisions on which orgs they will support this year).
I suppose I should say something about what you're volunteering for. By volunteering as a potential mentor, you'll have the chance to be involved in choosing potential projects to recommend accepting for the
haskell.org organization. Additionally, if a student is selected who you are interested in mentoring, you'll have the chance to work with that student. The commitment of being a mentor varies widely between students, anywhere from a couple hours per week to review code and give general advice to an advanced student, to 10+ hours for detailed guidance, pair programming, etc for a student who is newer to programming. (The time commitment and availability of a mentor who is willing to make the commitment is one of the factors we would weigh in matching students with mentors.) In any case, listing yourself as a potential mentor means you may be contacted by students working on proposals, but you will still have a chance to evaluate individual students and proposals and decide whether you are willing to mentor that project or not.
Again, let me know if you're interested.