The TYPO3 Core Team and the TYPO3 Community are proud to announce that the next major release of TYPO3, version 4.5, will be a "Long Term Support" (LTS) release. We now produce a new major TYPO3 release every six months, which means old versions become unsupported more quickly.
The Long Term Support version, however, will continue to be maintained and supported for three years. There is no extra fee for this special LTS version; our very best work is available to everyone on the same free terms as other TYPO3 versions. Upgrades to new versions of TYPO3 are and always will be free of charge.
Full release announcement: http://news.typo3.org/news/article/typo3-version-45-with-long-term-support/