The basic idea of MIR ("conducting a virtual orchestra on a virtual stage") will remain the same, which means that you will be familiar instantly with the the actual MIR GUI (although it got re-coded almost from the ground up). Apart from that, you will use MIR Pro like you would use Vienna Ensemble Pro - closely integrated into the DAW of your choice.
In the end, this means that you don't have to deal with two (or more) completely seperated applications any more. Regarding the workflow you may have developed with the existing version of MIR, this might be the biggest difference (... and we hope that this change will receive a warm welcome even by die-hard MIR users ;-) ...) .
Kind regards,
/Dietz - Vienna Symphonic Library