If you used AudioUnits plugins on the Mac then no, it won't be compatible. But if you have Mac format VSTs for all your plugins you use you can build your template with those and it will be cross-platform. When both AU and VST versions are installed on the Mac you choose which format to use when you insert the plugin.
I've done some testing between my MacBook Pro and Windows studio PC and it works beautifully. With VEP6 it'll be much easier to start a project on the road and transfer it to the PC when I get home. With VEP5 I've had to maintain parallel templates for Mac and PC, which is a royal pain.
I'm also excited about being able to deactivate channels and use my full template on the MBP, activating channels as needed to conserve resources.
Great stuff, really looking forward to the next updates!