The awesome bar uses historical data from previous searches, so if your search for "news" always ends with you clicking on HN, it will put that at the top. Over time, the bar will learn your preferences and become much more useful.
I hated the bar at first, to the extent that I considered going back to FF2. For example, I used to always type "en." to find a wikipedia page, but that no longer worked well. Now I love being able to type in parts of pages, and I no longer use bookmarks since I can just search my entire history. The only thing missing is the ability to sync the history and awesome bar training to other machines, which we're working on ( http://labs.mozilla.com/2007/12/introducing-weave/ ).
Disclaimer: I work for Mozilla :)