I personally have been using the beta version for the past 3 months and I have come to like it still better than I.E. There has been a few little bugs that I have come across but nothing to bad that I have pitched it out the door yet. The only drawback that I dont care for is the face that you cannot use most of the applications that are available for firefox 3...
The is scrambling to release Firefox 4 in 2010 means it's a frenzied time for Mozilla, but there's more afoot at the organization than just building a browser.
Specifically, Mozilla is concerned about how people on the Web will find and pay for the increasingly sophisticated online applications made possible with modern Web browsers.
"The open Web is a great platform for rich applications. It would be even better if it had additional capabilities to ease discovery, acquisition, installation and use of apps, while also enabling monetization for developers," Jay Sullivan, Mozilla's vice president of products, said in a blog post announcing the work. Read More at Cnet
Give Firefox 4-beta a test run