Large, powerful content creators and networks (networks are also distributors of content) tend to have more power, and one generally can say that in those cases--ESPN for example--it is the content packager that is "king." But ask any of the lightly-viewed small networks carried on cable, telco and satellite networks whether content or distribution is "king," and you are likely to get a much-more-nuanced answer. Small networks have to fight to get distribution, and might well say distribution is king.
To become a top 1,000 website you need at least 4.1 million visitors per month. To become a top 500 website you need at least 7.4 million visitors per month. See http://royal.pingdom.com/2010/07/05/what-it-takes-to-be-a-top-100-website-charts/ for more detail.
To become a top 100 website you need at least 22 million visitors per month. To become a top 50 website you need at least 41 million visitors per month.
For most websites, distribution would appear to be "king." In every case, if you are one of the small number of market leaders, content is king. For most organizations, distribution is going to appear to be the bigger business issue, and so distribution would remain king.
