I'd give my money to Roush before Saleen, but there are plenty more very respected GM tuners out there that I'd go to first. I can totally see the angle that he may have been taking in that video - he was at a Mustang/Ford-deal, but in this day and age, I think it's pretty careless to think negative comments you make in public against a product or project you undertook (not to mention not completely represent correctly (i.e. the V6 thing)) won't affect people's opinions to whom you plan to appeal to later down the road. Did he think that he wasn't going to try to make a SMS Camaro down the road and that it would be okay to do a little bashing? Maybe, but doubtful - I think. I'm sure he had plans since it was stated to go into production. Does he think his name will automatically bring enthusiasm to his product just because of his name, despite the fact he was bashing the product not long ago? I don't know.
For me, I'll be doing my own thing with someone else. I don't wish ill on him (although I've had unpleasant things to say about him in the past) but everyone is entitled to do what they want with their car and their money