that was one of my thoughts, i guess it all depends on how developers choose to distribute their demo's, or if they even choose to submit a demo at all!
The more i think about it the more it seems like the best way to go would be offering demos's to be played through the site, if the developer has an installable demo offer a download link and failing both of those, allow video/image previews.
I want to give developers/publishers the best chance they can get to shout about their products and provide a valuable sales platform within