Kudos to dos1 (of shr-settings fame) for bringing up a patch that we had applied to SHR removing e-wm-utils, a new enlightenment package, that did not work with our old enlightenment version. Now that we upgraded, it proved crucial -- and left us scratching our heads.
Thanks to dos1, we have our icons back. If you have a broken unstable installed, fix it by installing the missing package:
opkg install e-wm-utils