Hi,
I did an undergraduate in sports science, and now i'm studying physiotherapy so I guess that means I qualify as one of the 'new breed'.
Id say the main benefit of the additional qualification (i dont believe it has to be a degree to be honest - but maybe employers would, im not sure) is that it gives you a better understanding of the whole process from injury back to elite performance. Its not relevant to the vast majority of the population but generally the higher the level of sport the more that is physically required. A physio degree gives you what you need in the injury/rehab of injury phase and the sports science degree gives you an in depth understanding of whats required for higher performance - such as at elite sports teams which is possibly where that 'new breed' term came from.
To me, i certainly see it as an advantage having a wider knowledge but most of the top sports teams employ sports scientists and other fitness coaches seperately. The physios job is to rehab so I dont see a sports science degree taking presedence over relevant physio experience for a physio job at a sports team. Someone like Jensen Button is slightly different as hes one person, if one person can help him with both his injuries and peak performance then it'd be a big benefit there. Why employ two people when the job could be done by one. I read the article you're talking about and I think to get to where he is, hes got more than the two degrees on his CV, probably vast experience.
In my opinion its like anything, the degree will give you good groundwork but the real learning is to be done on the job. Theres nothing to say a physio with no degree in sports performance but loads of experience in sport can't be just as knowledgable about elite performance as someone who has one.
That said, if you give yourself a bigger groundwork it can only be a good thing. I rekon a smaller qualification, maybe a diploma in something sports performance related, and then tons and tons of related experience would be just as beneficial as getting a second degree. Thats the route i'm taking. I'm doing the 2 year accelerated MSc post grad and i've heard people on here saying they wouldnt employ anyone who's done that degree as it's not enough time to learn. The only way you can counter such opinions is by having additional experience.