Mozilla has launched an updated nightly version of Fennec (Firefox for Mobile) which will run on Android based Tablets. According to the comments it also will work on Nook Color running CyanogenMod 7 as well as on some other OS such as Linux with a little hacking. Keep in mind this is still a nightly build, so there are still a lot of bugs and kinks to work out. One of the main bugs right now is the need to add a way to hide the tabs sidebar in landscape tablet mode. However, this will at least show the UI for the future of Firefox mobile browser.