Opera Next is a separate installation of the Opera browser that lets you try our latest pre-release versions without affecting your main Opera installation. Look at the new release cycle, what and how Opera next will work with some basic FAQ’s.
Mozilla has planned to release Firefox 4 beta 10 by January 24 and beta 11 by 31. So there will be two more betas before release candidate(RC) which is planned to release in early February.
While Building Firefox 4 Beta 8 Mozilla team found an issue with localization repacks. Beta 8 will be released on December 21 to public along with Fennec 4.0 Beta 3.