Why FireFox : Automated update; Faster browser navigation;Drag and drop browser tabs; Improved popup blocking; Clear Private Data; better product usability including descriptive error pages, redesigned options menu, RSS discovery, and “Safe Mode” experience; Better accessibility support; Better support for Mac OS X (10.2 and greater); New support for Web Standards including SVG, CSS 2 and CSS 3, and JavaScript 1.6; Many security enhancements. Read the Release Notes for what’s new in 1.5.
And once you have it, try some Scalable Vector Graphics SVG stuff like this this or a Tetris Clone, and other demos; or like this demo showing off the capabilities of the new Canvas tag with Canvascape – “3D Walker”, a simple javascript browser based 3D first person game engine. Can’t do that in IE
