So Google is jumping into the open source browser biz with Google Chrome. What's so different with that compared to Firefox and Safari?
Instead of following Google's comic done by Scott McCloud (at http://blogoscoped.com.nyud.net/google-chrome/ since the regular site's being Slashdotted), let me try to tell you about it this way.
Remember back in Netscape 4.x that you didn't have tabs. You had a ton of windows. IE up to 6 has this too (7 introduced tabs, as did Netscape 6). What a mess! Tabs helped, but it was still controlled by one instance of a program.
Now, instead of one instance with multiple tabs, make every window be a seperate instance of that program, and swallow all the instances into the main window. Each instance is accessed by tabs. Popups are swallowed and put on the bottom of the tab until you ask them to. Close a tab, close the instance. Memory is handled by the OS, not by the browser, so slowness is a fault of the OS or an external program not handling it's memory. Security gets enhanced because no site can futz with another site -- infact, the instance is reset when one domain is swapped out for another.
Check the comic out. I just hope they make the omnibar optional.