Got a spare RasPi knocking around? Why not hook it up to your all-in-one and use it as a handy print and scanner server?
I have previously tried to get my multifunction printer/scanner working with OpenWrt, but ran into difficulty with the scanner. Having tried it with the RasPi, I'm pleased to report that it's as easy as Pi ;)
Print server capability is provided by the Common Unix Printing System (CUPS), and scanner capability is provided by Scanner Access Now Easy (SANE).