What is the story with Austin, Texas? Cool capital?

It's the state capital of Texas with a small population, compared to other U.S. cities (under 1.9 million). In recent years (2008-2009) more adults in their 20's and 30's moved to Austin than any other U.S. city. Why? Creative, divergent thinking people choose to live there? Hipster reputation? Arts and festival scene (e.g. SXSW)? Austin bills itself as "Austin, Live Music Capital of the World" so it must have a thriving live venue scene.
Take film directors - arty Terrence Malick, quirky Wes Anderson (Didn't you love "Moonrise Kingdom"?), Tarantino buddy and multi-tasking Robert Rodriguez, horror buff Tobe Hooper - all come from Austin or call it home.

I just finished a weird hobos-on-a-quest book ("Mr Shivers") written by Robert Jackson Bennett. Where does he live? You guessed it, Austin.
My 20 year old daughter's favourite Internet comedy group (at the moment) is Rooster Teeth - based in Austin, TX.
There is a pattern here.