If you'd like to help us make Oxygen or contribute in any way please join the irc channel #oxygen on freenode.net or send a mail to the kde-artists mailing list (all@oxygen -icons.org) or (firstname.lastname@example.org). One of the teeam is almost always online. We'd love to to discuss the possiblity with you :-)
In order to coordinate the addition of icons to the theme itself, all external artists should send their work for review to one of the refered emails, they will be reviewd for licensing of the theme and the compatability with the guidelines for creating Oxygen icons.
Contributors should realize that the Oxygen icon theme mantainers can (and probably will) modify, delete, reuse contributed artwork.
The Oxygen Team