Aggregators abound, but the newish site Fwix.com has found a formula that translates content into local streams. It's yet another challenger in a crowded field, but its algorithm appears to have a strong scraping capability that yields a relevant result. Until now, though, it hadn't developed a commenting capability.
The business model seems predicated on display advertising, but the site plans sponsored links to more broadly support content.
It's not necessarily in line for any design elegance awards, but its utility is more valuable than its look and feel.