Support for Red Hat Enterprise Linux Improved Through Enhanced Product Life Cycle

Updating the Enterprise Linux Life Cycleより、

Everyone,

as of today, the first phase of the life-cycle for every Red Hat
Enterprise Linux major release is being extended from three years to
four. During the first phase of the life cycle we provide support for
new hardware that is released by our partners, important new software
functionality, bug fixes and security patches.

このため

One immediate effect of the change is, that Red Hat Enterprise Linux 4.7
will *NOT* be the last release in the Enterprise Linux 4 life cycle to
enable new hardware: 4.8 is planned for early 2009 and *will* contain
limited hardware enablement. After that we will enter the Production 2
phase and newly added 4.9 release will then be the final, bug-fix only
minor release marking the transition into Production 3.

とのこと。RHEL4.8が半年後、RHEL4.9が更にその半年後といった感じだろうか。

Red Hat Enterprise Linux Errata サポートポリシーより

Red Hat Enterprise Linux (version 4):

Red Hat Enterprise Linux AS, Red Hat Enterprise Linux ES, Red Hat Enterprise Linux WS, Red Hat Desktop
米国における製品初期出荷日:2005年2月15日
フルサポート終了日:2008年5月15日
デプロイメントサポート終了日:2008年10月31日以降
メンテナンスサポート終了日:2012年2月29日 

なのが、Red Hat Enterprise Linux Life Cycleによると

Red Hat Enterprise Linux 4
General Availability: 	February 14, 2005
End of Production 1 phase: 	March 31, 2009
End of Production 2 phase: 	No earlier than Q4 of 2009
End of Production 3 phase: 	February 29, 2012

になるということ。