Branson is just the type of owner that could use employee attractiveness to differentiate his product from the others. As I see it now, the airline industry is in a sad shape, expensive, homogenous, and bland, not to mention treating their customers like criminals. It needs something to make me want to get back on a plane. Attractive attendants might do it.

On my first Virgin America flight (very soon after they started) the flight attendants were unusually attractive young women, one of them especially so. A lot of heads would literally turn when she went by. I overhead someone asking her how she got the job and she said "I was recruited." So that's one data point...

AFAIK Virgin is no less unionized than BA.

I believe they are already exploiting this, see their 2011 advert that was shown on TV in the UK - http://www.youtube.com/watch?v=Hbib-A6NpW8

Also, their 25th anniversary one (2009) takes a similar track.

When Virgin Atlantic started their FAs were young and very pleasing to the eye. However they are also unionised, and as such will suffer the same fate as the rest of the airlines.