We package GNOME3.
To join this team go to #ubuntu-gnome and introduce yourself. To be a member you should have good experience with updating packages. If you are still learning, the best thing is to propose merges into the package branches (lp:~gnome3-team/package-name/ubuntu) and ask for help in #ubuntu-gnome.
Discussion about GNOME3 on Ubuntu should be done on the Ubuntu GNOME mailing list: <email address hidden>