There's some discussion around the web based on scuttlebutt that Google may be seeking to build it's own browser. Ars Technica points out that Google could easily enough build on top of Gecko or KHTML.

But one thing I would like to point out is that so far, discussions seem to assume Internet browser as the main purpose behind such possible development. Why assume merely an Internet browser? Look at Konquerer and then Ars Technica's previous point about Picasa's search technology. The killer browser is the killer complete browser--file, image, document, Internet--everything through one app.