There's enough material on the web at this point that a list of other peoples lists and personal collections probably has more value on average than a news aggregator.

The strategy this implies is going a further level up, which implies going a further level up, etc etc.

EDIT: I changed my mind, but don't feel like going into detail here. The problem with these lists is that there's a lot of repetition. If everybody would list their books in the same format you could get rid of the repeats and leave only the books that have been recommended by a HN member. Bonus if you can put the descriptions into a structured format as well.