http://en.wikipedia.org/wiki/Alcubierre_drive
A lot more work needs to be done on this because there's many assumptions that have been made which will probably prove false. It's only because of our limited knowledge at present that we can't see beyond the problems. It will probably take some new form of physics.
There's to many "if's" being touted for and against, so I don't think they really know what to do with the physics as it is. For now, anything said for and/or against is pure speculation.