Could be worse - last year CBS usually showed only 3-4 of the most popular games in HDTV. CBS simply is cheap. (I recall Steelers-Raiders and Steelers-Browns in Cleveland were SD last year)
CBS apparently increased the HDTV offerings this year because showing so many SD games in 2006 was starting to hurt ratings when Fox was broadcasting a competing HD game.
That stiill involves having SD broadcasts for less popular games, which has involved a lot of Jax and Browns games (and Bills-Bengals last Sunday) but rarely the Steelers, who are a big AFC draw for casual fans.
The NFL supposedly has mandated all games are in HDTV next season.