Yeah I know Comcast (and other iGuide cable ops) let's you choose a few things:
1. Guide color scheme
2. Double line or single line guide (single gets more channels at once)
3. Two or three channels on the mini guide
However for the last 10 years, I-guide is relatively unchanged in looks.
That would definitely be a nice set of options. That blue "glow" effect will get stale after a while. Just being able to choose a different color would be nice, although I could even go for themes... sports teams, holidays, favorite show, etc.
I also don't see why the guide can not be customized. Users should be capable of deciding how many channels and how much time their TV can display and their eyes can read. Least common denominator is never a good reason for a design choice like this.
All things considered though, speed improvements will be a welcome change.