Epson's PictureMate Show isn't quite a sleek digital photo frame with hidden printer, but if you wanted to print 4x6 images at home (and nothing else), it's a fairly elegant solution.
Featuring a 7-inch LCD face, the Epson PictureMate Show is half digital photo frame, half small form photo printer. You can load images via USB or card reader, edit them using the display and then print them at a class-leading 5760x1440 dpi. The PictureMate Show is $300 and available now, but unless you're printing stuff you really don't want other people to see, I don't really understand the economics or convenience of mass printing at home. [Epson via Electronista]