A general wordpress pageload depends on loads of plugins and such and in my time with wordpress (approx 6 months now), I have always felt that WP is somewhat sluggish on a medium load website.
Mysql handling is fairly decent from what I can tell from my tests, but parsing the the content is what takes up the bulk of the time. Since I don't want to change the core files, I have reverted to plugins such as wp-cache which work, but are not ideal.
p.s. I know speed is influenced by a million factors, but I'm running a p4 3ghz, 2gb ram, apache 2 machine and even with a default wp install I can't get apache bench to give out more than 5 or 6 requests per second. That = slow.