On HDTV, the text is a bit smaller, and sitting on average 10-15 feets away, it's hard to read if any bright scene's are on. Sure, if it's dark, it's easier to read, but is someone supposed to skip to a darker scene before being able to change it. I took some screenshots to better illustrate an example of the action in play.

As you can better see, when sitting 10-15 feet away, the text is harder to read then using a SDTV with big text. And i didn't even bother taking a snapshot of 1080i mode, because the text is much smaller yet and didn't even show. I know most don't use 1080i due to the xbmc being flicker with motion due to the xbox power limitation, and 720p looking just fine.
Here is a quick mockup used just to quickly show even a 10-15% transparency added, is enough to allow text to be readable more easily. Granted i did a quick darken, so you just have to imagine all text itself being a bit brighter, since the effect was added to everything in the box area.

If you send me the proper file, i will even do it myself and test. It'll be worth it to me, and to others to include this. Please at least consider it. People won't be able to use older SDTV technology after 08 anyway, because of FCC new laws, so they need to upgrade anyway. We really need to not leave out the HDTV users.