Jet Blue adding a non-stop to LA to their RDU routes is a big deal if it turns out to be long term. The only other "budget" options to LA involved a lot of weird changes and complications. And as Andy notes, it might drive down pricing for Delta and American a bit ... which would also be good. I've had decent experiences with Jet Blue and find them to be on par with Southwest (or better, depending on the route) in the budget category.