I remember this being discussed in the past, but seems that a few problems exists and nothing was concluded.

It would be nice to have a way to create a database with a default collation when a default charset was specified. Something like " CREATE DATABASE blblabla CHARSET xxxx USING COLLATE yyyy" or any better syntax (maybe ANSI SQL has something defined for this).

Also, in a talk with Adriano, he proposed another DDL command like:
ALTER CHARACTER SET <X> SET DEFAULT COLLATE <y>