Well, we saw it coming long time ago, as development on PHP 4 was ceased in 2007 and phpbb 2.0 branch runs mainly on PHP 4 codebase, developers of phpbb found it unwise to continue support of outdated software and require people to install old PHP in order to use phpBB.

That’s why they announced retirement plans for phpBB 2.0.x:

1. Wednesday 1st October 2008 - download links will be removed from the download page at phpBB.com of course you can still download it from SourceForge.NET
2. Thursday 1st January 2009 - phpBB 2.0.x will be formally retired, and support will no longer be actively provided for 2.0.x. Converting from 2.0.x to 3.0.x will continue to be supported
3. Sunday 1st February 2009 - Security patches, if required, will be provided by this date

as for modifications for phpBB 2.0.x they will retire too:

1. July 1, 2008 - MODs for phpBB2 will no longer be accepted into the MOD Database. Updates to phpBB2 MODs that fix security issues will continue to be accepted. [2.0.x] MOD Writers Discussion and [2.0.x] MOD Requests forums will be set to read only. [2.0.x] MODs in Development will be changed to not allow new topics but replying to existing topics will still be allowed. [2.0.x] MOD Database Releases forum will not change and will continue to operate the same way it has been.
2. February 1, 2009 - all submissions of phpBB2 MODs will no longer be accepted into the MOD Database. [2.0.x] MODs in Development and [2.0.x] MOD Database Releases will be switched to read only.
3. May 1, 2009 - all of the forums will be closed and hidden from public view. All downloads for phpBB2 MODs will be removed from this site.

phpbb 2.0.x is dead, long live phpbb 3.0.x