While governance is a good start, IT responsiveness is critical to controlling Shadow IT. If someone is put in a position of not completing a project on time, or waiting for IT to get around to their project, or if IT Platinum plates the solution to drive one of their projects, that person feels trapped.
The obvious solution is to create their own IT solution, under their desk that no one knows about.
As for the cloud, it's over rated. It's not the silver bullet that solves most problems. Sometimes you still need good old fashioned analysis that's so hard to come by these days.
While governance is a good start, IT must be responsive and cost effective. If not, shadow IT will thrive for a very long time.