Things you can do if you want to help:

 - Porting gossip-account-widget-*.{c,h} from gossip project (Guillaume is already working on IRC widget).
 - UI for inviting a contact in a chatroom.
 - UI for accept/refuse invitation to join a chatroom.
 - UI to send a message directly to a contact.
 - GtkWidget-ify libempathy-gtk. Actually most window/dialog do not inherit from GtkWindow/GtkDialog. Need to create a glade catalog.
 - Remove Quit option everywhere, empathy is a session service and shouldn't be leaved.
 - Add sound events
 - Add register capability in EmpathyAccountsDialog if the profile says it's supported.
 - Write a manual based on gossip's.
 - Testing and Bugfixing.
 - Update translations.
 - Fix indentation and alignment broken since namespace changed from gossip_ to empathy_

SoC projects:
 - Adding VoIP support based on the patch proposed for gossip.
 - Adding FileTransfer support.
 
If you want to contribute you can ask for information at
 - #telepathy on freenode
 - Telepathy's mailing list: telepathy@lists.freedesktop.org