Edit: Since I am about to become a Comcast sub by default, this news bodes well for me. I've had one of my two current HD DVRs, the SA 8300 HD, in use for about a year now and though they are both rock-solid in terms of dependability, in all honesty they lack some of the bells & whistles of the TiVo.
I welcome this news and look forward to comparing the two units side-by-side.