Yes, TiVo Series 3 (just out) no longer needs a cable box at all -- it accepts two CableCards for local decryption, and can then record any two subscribed channels at once while playing a recording back.

Intriguing. Do we know if Comcast is currently providing Cablecards? (And whether it costs extra to get two?)

While I've been vaguely aware of cablecard technology for a long time (since my father is always off on the bleeding edge of home technology), I haven't had any reason to investigate it locally before.

Very useful intel. Thanks!