Also regarding the overscan issue, I remember reading a thread here about Jonathan Blow or some other indie game guy discussing the death-by-a-thousand-papercuts that getting approval for a WiiWare game was. One of his main complaints is how Nintendo required at the time that all vital screen elements reside in a "screen safe" area. His argument is that every single one of the additional little requirements that Nintendo imposes on its third party developers results in additional cost and labor on the part of the developer, to the point where it was onerous.
As far as I can see it there are three ways that you can deal with overscan.
1. Require developers to place all vital visual elements in a screen safe area. This results in kind of a dumb buffer area at the edges of the screen that most people will see because most HDTVs are 1:1.
2. Require developers to respect a system-level overscan setting. They can set their engines to render at a particular resolution and shift HUDs, menus, and so forth so that they can occupy any resolution between 1180x620 to 1280x720 or whatever.
3. Scale the image down at an OS level. This will affect performance and cause artifacts.
In my opinion, Nintendo looked at these three options and decided that the drawbacks for each was too great compared to the percentage of TVs that force overscan.