Fennec, otherwise known as "mobile Firefox", is on the way! Recently Mozilla released an early developer alpha (testing only for now) of the browser, and it's great to welcome a quality, open source mobile browser to the scene!
Currently you can install Fennec on your local Mac, PC or Linux box, and it also runs on Nokia N810 devices. I installed the Mac version on my own, and it's pretty rough. But they told me it would be, and this should evolve into a really nice, standards-compliant mobile web browser in the future. Keep an eye out for it!