I've added The StatBot to my must-read blogroll - they put together some fascinating analysis and statistics across top web 2.0 sites... oh yeah, it's done by a 17 year old "wannabe geek from India". The result is amazing analysis that showcases the power of distribution, platforms and open-APIs.
Here is a charting of Digg's popular headlines compared year-over-year. Digg is considered a haven for techies - but if you scan left-to-right, you'll notice that the headlines have become increasingly mainstream in 2008 (pics, Clinton, Obama, CNN, Economist, etc). 2007 was predominantly driven by gadgets: Vista, Wii, Sony, Nintendo, iTunes, iPod, etc. It's tough to tell how much of this trend is due to the fact that 2008 is an election year - but the shift from tech to pop-culture suggests that Digg has:
1) expanded their userbase 2) developed depth beyond technology 3) is a major news source / community for news, politics and commentary