I went to Open Database camp a few weeks ago. There was a talk about the split...

The short story: MariaDB is a fork of MySQL done by Michael "Monty" Widenius one of the mySQL founders.

It seems the winds of fear are blowing against mySQL and MariaDB is getting mindshare (it is a fork so pretty close still but not going back). Although Oracle hasn't really done anything yet, and did send a rep to the conference, there seems to be some distrust.

About a decade ago at a startup we had and Oracle instance running s a test, their sales people where tenacious (fought them off by asking for an ODBC driver for linux). Then startup went under. sigh.