of coz this comparison is flawed from the beginning.. I doubt there is a true 720p TV in the local market (unless you are using 720p projector)... more like 1366x768 for the current crop of panels

any one who knows LCD monitors and computers knows is best to drive the resolution same as your LCDs native resolution to get the optimal effect....

so driving 1280x720 (720p) data into a 1366x768 LCD panel is bound to have up-scaling and alisiang artifacts...

finally who also will know it's better to go with more resolution if have to choose between a HDready 1366x768 vs 1920x1080p TV panel...
it's really a matter of costs and how much you willing to fork out..

well it comes down to how far you sitting back to be able to see the difference... why do you think 24 inch LCD monitors got 1920x1080p or more, cos you are like 1-1.5feet away..
also as you said, the source (in this case the game) needs to be 1080p originally... how frequent is that? (not taking sides but I'm sure some folks derived their simplistic conclusion from playing many normal 720p games hence they feel not much improvement over HD ready TVs)

so it also depends on your "source collection" of viewing materials and games.

hehe sure mah!... if all you have is 720p sources from video and games.. then getting we wont really gain much more image definition moving up to 1080p screens

that's a different topic altogether..