NYTimes.com's RSS feeds generated 5.9 million pageviews on the site in March, which represents a 342% increase year over year and a 39% increase from February's 4.3 million pageviews. The sections that were most popular among RSS feeds included: Washington and Business. The feeds have been available since February 2002 (www.nytimes.com/rss).
Granted, RSS views account for only 1% of the total views, but 5.9 million pageviews is not an insignificant amount of traffic. The growth rate is equally impressive.
As many of you know, NYTimes only offers excerpts in their syndicated feeds; you have to visit the site to read the full article. I doubt they would generate nearly this level of traffic if they delivered full-text feeds.
It does seem a little premature to say RSS is a key driver of traffic. The increase in total traffic suggests that RSS is creating a larger total pie, but of course there are other factors that will contribute to that growth as well.