I did a clean install of the public beta on my 2009 13" MBPro. When I tried to install the printers, it said I had to download from the vendor. My printers are a Brother HL-5250DN, Epson Stylus Workforce 635 and Epson Stylus Photo R3000. All had drivers included by Apple under Mavericks. I wonder if this means that there's enough of a change in the printing subsystem that old drivers won't work? That doesn't bode well for older printers that the vendor may not update drivers for. Anyone else find this?