Can I create a Mavericks installation in VMWare Fusion and migrate that to the native disk? My current installation has become kind of cluttered and I want to create a fresh one in VMWare. When the one in VMWare has everything I need, I'd like to migrate it to the native disk, so it become my main (normal) OS.

Is that possible?
Make a Time Machine backup from within the VM and use this to restore the native machine once you've re-installed OS X there..

I do not know if all drivers are installed at all times (doesn't happen for Windows) so I would be a bit wary of using cloned disks to do this.  Much rather let Time Machine do what it is designed for.