I have successfully installed gallery 2 beta 4 on Alpha26 using the Dan Brown "How TO" with only minor revisions (newer sources for files) Works great!
I have also installed php-nuke into a different i-bay on 7.0 Alpha 26 using the information from
http://forums.contribs.org/index.php?topic=19053.msg75348#msg75348
I am working on combining the 2 into 1 i.e. Gallery2 as a module in php-nuke on 7.0 alpha??