from:

http://konttoristhoughts.blogspot.co...73851680035486

"Fash is supported in fennec, but not in the default browser. We wanted to keep a clear differentiation between "desktop" -alike browsing and mobile browsing. Default browser focuses entirely in one handed use and relaxed browsing, where as fennec just does it all and acts like a desktop browser (tabs and all)"

finally some good news!