While granted, one should probably know who one is mentoring, sometimes a person forgets. Would be nice to be able to look it up somewhere. "/mentor list" maybe.
If it already is there and I've just missed it, anyone care to enlighten?

am I really the only person who wants this?

yes

don't you add your students to your buddy list?

Yes I do. I have a lot of buddies though. If I come back a couple days later, and all I remember is that that person's name started with S... I'm in trouble.
Just would be nice to see is all.

I'd be your buddy, but I don't trust you not to abuse the information. :P