Ooh, la la! PVR Wire got their hands on a Series 3 TiVo and documented every step of the standard undressing ritual. You can see the two CableCard slots, the cable and antenna in, and lots of output slots as well. There's also the standard phone line, plus an ethernet port and USB ports.
Here's everything we know to date about the TiVo Series 3 DVR. Click the link for even more pictures.
Tivo Series 3 Unboxed [PVR Wire]