We made a few notable changes, including revamping the "add a feed" page by adding clearer feedback and better instructions. We also made the feed adding, indexing and aggregating a lot more robust by fixing some bugs deep within the feed processing engine.
We're trying our best to emphasize that this is a social news site, so we added the orange button (on the right) to encourage people to add their own content.
Coming in the next alpha build: the much anticipated search feature, along with perhaps some personalization and/or user profiling bits. More about these new features to come....