Google's own browser has launched. Called "Chrome", this browser has inherited some features from Firefox and Opera, and since it's open source, will be able to contribute code back as it evolves.
Check out Google's comic book describing the browser.
It will be interesting to see if this seduces Firefox and Opera users away, or if it hits Microsoft by enticing IE users to switch before they release IE 8 into production.
If Google manages to draw users away from Microsoft Office applications like Word and Excel and into Google Docs, they'll really be hurting Microsoft where it hurts.