That's really weird that they would go ahead with a production like that without having first secured music rights. The music in the trailer is really off-putting and generic (to a guitar player - but who else would go see it?). It stuck out right away as being inauthentic, so I'm not sure the movie is exactly destined for greatness.
Having said that, they made Good ol' Freda with only four Beatles songs. But of course that's four more than this Hendrix thing has. Doesn't mean I won't watch it, but I won't be paying to see it in a theater.