I suppose I would edit on Vegas 5.0 the way I had done in the rough cut. Not being able to work off of the rough cut audio mix would be a nightmare and I'd have to basically remake the audio from scratch.

EDIT: Although if I decided to do that I would redo it in 5.1. The original idea was encoding matrixed 4.1 PCM, but I don't know how many people have the Pro-Logic decoders anymore.

And in that case I would buy newer, faster editing software that I could use on the mac. Something like Final Cut Pro.