John C. Dvorak has a good article in PC magazine about web site entropy and website usability. I listen to Dvorak when he joins Leo Laporte on "this WEEK in TECH" - a podcast I highly recommend. This weekly podcast covers everything you need to know in tech which relates to marketing which relates to communications and on and on and on... I like Dvorak's examples that illustrate "keep doing what works." It's amazing how often I hear about a company that develops a great website, maybe even knows why they're doing great, and their first inclination is to change it. There is something about the internet that encourages constant change. Granted this is preferred over stasis, but change for the sake of change is not always good. If people enjoy your site, do not change the things they value. It seems self-explanatory, but it is shocking how often this happens.
Dvorak also mentions something at the end of his article that I think needs more illumination is that simple is better than complex most of the time. Why is Google one of the most popular sites? Take a look. Seriously, go to the site and don't search; just look at it. So much white space, so simple. I remember hearing an interview with Marissa Mayer discussing what an application had to go through before being posted to the front page (hint: it's A LOT). So when you go to Google.com and notice Maps and Images and such, those links have proved themselves to take up that space.
Compared to Google though, try out Yahoo or MSN. Try using one of these the next time you need to actually do something. They try to be everything to everyone and hence are doomed to be nothing to everyone (hyperbole, of course, since these two aren't hurting, but the theory remains sound).
The point is not to dumb-down everything; it's just to 1) do what you do really well and 2) don't worry about a whole lot else unless your audience wants it. When people (and more importantly, companies) start to think of their website as a tool, things will start to improve. If your website is a means rather than an end, you're one step ahead.