Forgive me for asking such a basic (perhaps even idiotic)question, but I haven't been able to find anyone with an answer... Are HD broadcasts in 16:9 format or 4:3 format? I just purchased a 4:3 format HDTV, with the anticipation of eventually receiving HD programming from my local cable company (Time Warner in Tampa). Should I expect to see received signals as 16x9 (black bars on top and bottom?), or will programming fill entire screen? Or is it specific to the program??? Thanks for help!