Someone should probably point out this is a good thing.
It's exactly how Apple does it with the iOS platform - some apps are targeted exclusively at the iPad, and the App Store filters on screen size. Some people say this is fragmentation, but I think a better term would be specialization. All platforms do it - the question is how easily the platform lets deal with it. I think Android does it pretty well (as does iOS).
If you want to target the low-resolution devices then you put it in your manifest and it will appear in the market.
I'm sure the same thing will happen with Google TV - some apps will be designed exclusively for Google TV, and so won't appear for phones. Doing anything else would kind of miss the point of the market!
(It's also worth noting that many Android apps have download links from a website, so if you really, really want to use an app that isn't designed for your device you probably can)
