Tresemme Beauty-Full Shampoo and Conditioner (reverse washing)?

I notice there’s been a lot of buzz in the beauty community lately about Tresemme’s new Beauty-Full line which is apparently specially formulated for you to condition your hair before shampooing to help give your hair volume without weighing it down like the traditional shampoo then conditioner method.  This sounds a little gimmicky to me, but lots of people are swearing by it.  Is there any science to back up whether this method and product will actually work?