Site looks good. Here are a couple things I would do (not necessary, just a preference)
Add a couple more links to your nav bar. Even if they are just a "contact" "about us" and "rss feed". I feel that a populated nav menu makes the site seem more content rich and legitimate.
Also, there is an exceptional amount of white space.You could change your header a bit so that it has some color or implement some other colors into your design.
If you are looking for people to actually read your latest tweets, i would take it out of the footer and put it somewhere else.
And I second what everyone else said about a search bar
Site looks great though. Like I said, these are just suggestions