For those who want to sort posts based on interests, Alex Chitu tells us that Google Reader has added a feature called "sort by magic" that can do just that.
Sort by magic replaces Google Reader's auto sorting feature, which Chitu explains is no longer available. The new feature works by prioritizing subscriptions with fewer items, according to Chitu. The setting prevents friend's blogs from being drowned out by higher volume sites, such as the New York Times, he explains. He also explains another feature called "popular items."