Completely agree with Darren.
Microsoft's cashback site will influence affiliate marketing to a very small degree, as any innovation does in this sphere, but the very nature of online business requires one to constantly have to adapt. Successful affiliates have always had to adapt to market conditions and, because their income depends on being sharp entrepreneurs and not succumbing to the constant barrage of assaults on their businesses from a million and one directions, there are no other bunch of people that I admire more.
I personally would not worry about even Google setting up a cashback site. Have you seen their level of support with Adwords? The first sentence of my email is always, "Do not send me a form mail response" and they still always do
