John Sheehan mentioned numbers the other day too - https://twitter.com/#!/johnsheehan/status/156271988195860480
Seems like the "Hacker News 10K" would be an approximate general number or its going to approach that soon.
My website is static, with no MySQL or PHP to speak of (by means of Jekyll), right now hosted on an AWS micro instance, served by Nginx. Prior to this it was hosted on Heroku's free plan, with offloading of static assets to GAE. For free and it didn't even blink.
Seeing how people are talking about caching, load-balancing, clusters, beefy servers and so on, just makes me think how extremely awful and bloated Wordpress is.