So is using the iTunes coloring algorithm enough to entice me away from Google News or Yahoo News or cnn.com or bbc.co.uk or whatever else I might use to get my generic current events updates?
You're right, a coloring algorithm certainly wouldn't be enough. Tightrope has a method to score and select media for 'Yesterday' and 'Trending'. 'Yesterday' gives a summary of the past day of media, while 'Trending' gives the bursts of media. You can read more on it here: http://blog.tightro.pe/post/40632430244/introducing-the-simp...
You would be better advertising those features rather than the colour thing which is unfortunately useless (although kind of cool).
OK but Google and Yahoo's news sites do something similar, at least as far as I can tell (and I'm a pretty technical dude - most users won't even understand that much). Again, what's going to entice me away from them?