Funny how time flies. Wikipedia is "more left" than Britannica according to <http://hbswk.hbs.edu/item/7689.html> and "there is room for both."
I do consult Wikipedia regularly as one of many sources. I do not use Britannica. It's online tools are privacy-bugged and except for the odd historical material in the library I have not used offline reference tools in a long while.
I have not contributed to Wikipedia for the same reasons listed in 2007, which is sad because I like Wikipedia and would like to see its contributing basis grow.
It is not for technical reasons: MediaWiki is great software and I used to contribute to more specialized instances of MediaWiki, then life got busy and I lacked time.
StackOverflow has evolved into an amazing network of knowledge collections. There are no excuses for not contributing to StackExchange, really, other than lack of time and deference to established experts that answer questions regularly.
I still love the Internet, despite Google and Facebook.
I have not checked wikipedia for a few months^H^H^H^H^H^HYears and to be honest I did not miss it and will most likely stay checked out. I had a reflection back in 2007 and decided that wikipedia as it stood then did not work for me. To cut a long analysis short:
Wikipedia lacks mechanisms to protect real knowledge from self-proclaimed "knowledge police"
Wikipedia is subject to mob rule
Wikipedia lacks reliable mechanism to distinguish authoritative contributors from charlatans.
Fear not, Britannica, technology and popularity are not enough to turn a website into an authoritative source. This is still true today. Even as some sites like Stackoverflow get somewhat around the difficulty of distinguishing a stinking fart from a noisy fart while on Wikipedia all farts are still indistinguishible, inaudible, invisible, and equally stinking (reputation metric!).