WordPress is great, but I am sure most people would agree that it can be a bit sluggish at showing pages. There is a lot going on behind the scenes to generate all your dynamic blog goodness, however most of it does not need to happen for every single visit to your site.
There are lots of ways to speed up performance of websites, especially dynamically generated ones. One good one for most occasions is to use caching to save on the time required to create pages dynamically. Whilst revisiting an old post on a friends blog earlier, I saw him mention the wp-super-cache plugin. I have had a look at it and have to admit to becoming an overnight fan.