Redirection
There is a good chance you have received 404 Page Not Found errors when visiting Joomla! built sites. They occur when modifications are made to the site that change or delete URL's of certain links. Even Joomla! official site can't avoid this problem.
A partial solution is introduced into Joomla! 1.6. Redirect includes a new plugin and a new component which automatically detect and collect 404 errors, and lets you assgin redirections for those missing links.
Beta 1, 2, 3, ...
There are other features being developed at the present time, but many of them are still in an early and/or uncertain stage. We will have to wait until the first beta version to see a more complete picture. But when will the beta be released?
According to Andrew, the target date for Beta 1 release is August 3rd, 2009. When the beta stage starts, the feature set is also frozen. Joomla! 1.6 will go through as many beta releases as needed to stablize the code base. However, the development team is hoping there will be only 3 or 4 betas with 3 or 4 weeks in between. With some calculations, you may realize that Joomla! community probably will have a wonderful Christmas gift this year if everything goes smoothly.
Conclusion
This coming Joomla! 1.6 may further push Joomla's maturity and popularity to a new high. Its vastly improved user management and access control will give extension developers better control over permissions and access, which will result better and safer extensions. Combining with the new nested categories, it gives site developers much anticipated flexibility.
To help with the development of Joomla! 1.6, you can join Joomla! CMS Development group on Google Group for discussions and suggestions. You can also download, install and play with the alpha version on your test machine, and report any problems and questions to development team. And, when the beta version is out, please start testing it as soon as possible so that we can weed out most of bugs in a short time.