I can see why the auto HD feature can be useful for some but its probably not a priority for TiVo since it would require a whole new channel mapping layer for EVERY market. Its easier for your comcast northern california corporation to do it since they are only worrying about the channel numbers in their market. Giving us the option would be nice...but personally one of my favorite features of the TiVo has been that I can remove every SD Channel from my lineup. Now when I go to guide I don't have to hit additional buttons AND TiVo suggestions will only record HD shows (there might be a new way to do it but I have always used this method).
In the bay area none of the HD channel numbers have changed dramatically, they conveniently start in the 700 and go to 840. In my opinion the easiest thing is to get rid of SD channels from your guide so the TiVo only records HD and after about a month you'll remember your favorite channel numbers...or you'll just start adding more SP. I still don't know what channel FX, USA, TNT, Comedy Central, HGTV, Food Network, or any basic HD channel are. I just record stuff and let the TiVo do all the heavy lifting.
When guest come over and use the TV they have no issues, maybe its because people in my age group 20-30 have never actually paid attention to channel numbers regardless and just look on the guide for the channel name.
Either way its down to the user, I can see how its more convenient for some but change isn't a bad thing, typing in 702 instead of 2 is just muscle memory after a month anyway.