A couple of links I found relating to WordPress scalability and caching.
Another Good WordPress And Varnish Article
2011Sun11Sep
Scalability,WordPress And Varnish
Filed in Blog, Category Hierarchy, Nginx Cache, Nginx Reverse Proxy, Podcasts, Telesales Experience, Using Wordpress As A CMS, Varnish Nginx, Wordpress 3.0 Multisite Experience, Wordpress 3.2 Podcast, Wordpress 3.2.1 Custom Post, Wordpress 3.2.1 Custom Post Type Plugins, Wordpress Admin Page, Wordpress Admin Panel
Wordpress Training
