Um, actually, no. You are not getting total digital. Coax is capable of sending a digital signal, but so is any copper wire. The digital box recieves the signal from the coax line and translates it and enhances it for HD. Much like a cable modem signal booster. It's like wearing 2 sweatshirts to look more buff. You still aren't buff. (pssst, I am good friends with the tech support manager at Comcast here.... I know a few things just by hearing his rants).
There are ways to go though. Comcast here has been running tests in certain areas using DVI and firewire, coupled through a fiber optic-to-component video connection. My buddy Clayton is part of this test and uses his 65" Mitsubishi HDTV. It is simply awesome. I have only watched tv at his place a few times, but it left jealous mark over my head. This connection is also capable of broadcasting 7.1 dolby digital in the bandwidth packets, so that too is simply awesome. Hopefully, the system works out well and the connection goes mainstream. I am told that a few more areas here have already been piped in with this connection, unfortunately, not where I live.
Basically, time will tell. If you look around most audio/visual stores now, you may see maybe 2-4 models of projection tvs. The rest of the massive stock is plasma or lcd. The phasing is already taking place and with better technology like blu-ray coming out, this upcoming year will be VERY fun and expensive in the home entertainment realm.
Gary Noonan
'01 S/C VX / '18 Forester XT