That's the point of 720? I think it's an annoying half-way step to 1080 which just causes more confusion for the consumer, and annoys people who have 1080 TVs and find out that some shows are only going up to 720!
I think they should only broadcast shows in 1080, people should be able to buy 720 TVs if they are too poor to afford a better one, but don't lower the quality of the source material for everone
Here's a list of TV shows in HD:
http://www.cnet.com/4520-7874_1-5119938-1.html
720 Shows include Desperate Housewives, Lost, and 24.