Rosetta and language pack updates

Hi,

I have some questions about the update process of language packs and the 
role of Rosetta in it.
Is it necessary to synchronize the GNOME-CVS with Rosetta to get 
translations into an update? Or will new translations by approved 
translators in Rosetta be included automatically into the updates of the 
language-packs? In other words, are only "green" translations included, 
or "violet" ones from Rosetta as well?
And what is the update-cycle of the language packs? Monthly? 
Six-monthly? And translations of which packets will be included? Just 
the Ubuntu-specific packets or also GNOME and other applications? I’d be 
glad if you could clarify that.
Regards,
Erdal