Please have a look at the TYPO3 4.6 wiki if you want information about the next upcoming TYPO3 version.
The TYPO3 4.7 project currently serves as a working ground for projects which are not planned to go into TYPO3 4.6 but are likely to be integrated into TYPO3 4.7 (or are released at the same time of TYPO3 4.7 in the case of major extensions like DAM 2.0).
Approximate release date of TYPO3 4.7: April 2012.
Collection of possible major features in TYPO3 4.7¶
Reworked history/undo concept and handling¶
The usability of the history/undo module in the backend is doubtable. The tasks is to improve the handling and also fix the concept in terms of workspaces and localization.
API (REST/JSON) to directly access elements/data of the system repository¶
Improved user authentication and permission management (roles concept)¶
The user permission handling in the backend is really complicated. The basic idea is to simplify that and to introduce a roles concept.
The authentication in the front-end requires several performance optimizations (currently it's initialized on each request in the front-end).
Static File Caching and improved per-object caching¶
The GSoC 2011 project on Static File Caching needs to be streamlined - besides that e.g. per-object caching can help to reduce redundancies in the caches (e.g. on using conditions or language versions) - it's about splitting up the information that is stored to the hash-value used for the pages cache.
Language handling and the L-parameter in the front-end¶
The language parameter is not mandatory and is implemented by using TypoScript conditions to set the sys_language_uid property. Thus language handling could be a mandatory concept and not an optional as it is right now.