Now here’s a significant new beta from Apple:

Having the navigation tabs on top is definitely interesting, as is the Top Sites which automatically pops up after launch. Of course, WebKit as well as some other extensions will have to tweak their code to take advantage of the new features.
Now where’s that Kent Dorfman sound when I need it?

UPDATE (02/25/2009; 1615 MST): You no likey tabls on top? Go here. Cut & Paste. Fixed!