We could organize intensive testing for Vietnamese, but I'm afraid we won't be able to test every single language provided by m17n-db... :-/
About the language-support-input-vi metapackage, I do confirm that adding scim-m17n is enough and does work from Hardy Alpha 6 (I've just tested it). It was not enough up to and including Gutsy because libm17n-0 didn't depend on m17n-db which is the case now.
We could organize intensive testing for Vietnamese, but I'm afraid we won't be able to test every single language provided by m17n-db... :-/
About the language- support- input-vi metapackage, I do confirm that adding scim-m17n is enough and does work from Hardy Alpha 6 (I've just tested it). It was not enough up to and including Gutsy because libm17n-0 didn't depend on m17n-db which is the case now.