This may not affect too many but many games are not working on HDTV's that do not support 720p. The xbox360 will downconvert and/or upconvert games but the PS3 seems to not have this ability.
From what I'm reading there is no scaler in the unit at all. If the chip isn't there then it will rely on software to run that process which will most likely cripple the system.
I'm not sure how many will be affected by this as my Projection CRT TV was bought in '03 and it has 720p but I'm sure many will be affected.