I'm ready to be flamed here, but here goes...
I drove a Honda S2000 in an autocross yesterday. The car is fantastic, but it made me realize that high-horsepower, high-rpm cars are a real chore to drive fast.
Maybe a V-6 would be worth the weight penalty...
Now don't get me wrong... there is definitely a place and need for a 4 cylinder, minimalist Elise. (I loved driving the S2). But I think that a V-6, if the weight is kept in check (say +100 lbs) could be a very, very fun car (if not as nimble as the S1/S2/S? Elise).
The car would be of a different character, but might be a good alternative to the retired Esprit.