I am working on something kinda-sorta like this, but I'm not so sure how to productize it. I think the industry as a whole has been held back by the "phone app" phenomenon because it discourages people from taking full advantage of the power of PCs.
The trouble is that you have to have an "irrelevance model" and that may be even more user specific than a relevance model. (For instance, anything about Apple is in my irrelevance model for HN) The irrelevance model may be more important than the relevance model because 99.9% of everything is junk, so the problem of finding actionable "news" is like making glasses that let you look at the sun.
