Take a look at the new Mozilla Labs web site, particularly their Concept Series. Don't be put off by the fact that some of the interface designs appear to be more about style than function, there are some innovative ideas buried in the design concepts.
I'm all for encouraging innovation in the web browser. If web applications are ever to be treated as first class software citizens then the user agent needs a makeover. The web browser is increasingly the main tool that people use to access and filter information, it deserves some attention when it comes to UI design and new standards.
I've got some ideas of my own I'd like to put forward. How would you design the tool that you use to filter out what you want from billions of pages of information and organise it in a way that makes sense to you?