I like Firefox.  It works well, robustly supports web standards, and generally is just a lot more pleasant than using Internet Explorer.   Given that I’m happy with Firefox, what could make me switch to a new browser?  

Maybe Flock has the right idea: integrate a wide number of web services (such as blogging and tagging) in a solid, open browser.   I’m trying to post this to my blog using the facilities built into flock as we speak.  Seems very smooth and well done.  I’m going to be keeping my eye on this one.