I will put it on my to do list. I had checked out the FamFamFam silk icons several years ago but the attribution requirement of the license was a problem because it would have meant all mojo sites must have a link to FamFamFam.
But some time since then FamFamFam Silk Icons, added a dual license under Creative Commons 3 and the attribution requirement was softened to he appreciates a reference rather than a hard requirement (apparently he did this so the icons could be used in Debian Linux).
So with the newer alternate license it is now compatible and possible to use the icons in mojoPortal without passing on an attribution requirement to all mojoPortal users. Actually using a few of them already in the new file manager UI.