Mozilla Foundation says it will launch its Firefox operating system (OS), which will be based entirely on HTML 5 and open Web standards, in order to unlock many current limitations of mobile Web development. It will target emerging markets, starting with Brazil in 2013. http://www.zdnet.com/mozilla-announces-firefox-os-for-emerging-markets-7000000163/
A few devs over at XDA managed to get a very early port of B2G and ported it over to S2 & Galaxy Nexus. It was still very buggy but it looked good as far as performance went.