Looks about right on my monitor (the pinstripes in the Mail background and the subtle graduation in the menu bar are clearly visible, those usually aren't visible with a too-bright signal), I would try calibrating your Mac (System Preferences, Displays, Color tab, Calibrate…, and check the Expert options button for more control). Also make sure your monitor itself has decent settings (see if Contrast or Brightness are turned all the way up, for example). Also make sure your monitor is terminated. If you use a VGA signal looping through something like a projector or a KVM switch or something, it needs to be properly terminated or you'll get overly bright, blown-out details such as you describe. Easiest thing would be to plug it into another monitor, if you have one available, that will narrow down where the problem is.
