From Macworld hints:
Delete your old Dell printer in the Print & Fax System Preferences panel. Install a new printer, but select the Mac-installed Samsung CLP-770 Series PS, and presto! You are back in business, complete with duplex printing and toner supply levels. Sweet!
I found you could just add an additional 5110 printer. It will try to revert to the generic drive before you select ADD but just reselect it and it will stick.