Guy Gavriel Kay used this convention a lot in his triology 'The Fionavar Tapestry'--at least in the first book. It took me by surprise, and I think he did it quite well. Just when you were getting sucked into the POV-trap of one character, suddenly, mid-scene, you're in anothers. Execution is key, however, and I can easily see this technique misapplied.