I always hear this argument that BMW needs an answer to the R8 or the SLS and I always think, "Why?" So some overgrown teenager can get excited by some car pron? Seriously, these are cars most (all?) of us will never drive, much less own, so who cares? If you think you're getting R8 DNA in your A4, fine, but understand they have about as much in common as Saabs and fighter jets (remember those commercials?)
On the other hand, BMW is actually doing something very innovative with the i8.