Hmmm interesting Frak. I think they kept it 2.0 to qualify for racing category purposes? I agree though a turbo model would be good or even a 2.5 with an extra 30nm, 20kw odd would have made a lot of difference and put it more on par with current ~200kw turbo hot hatches. I think a lot of the people buying these cars are satisfied with the power they offer, it would be a minority who want more performance but i guess those customers will shop elsewhere for a faster vehicle and have to dig a lot deeper into the pockets.
Its like toyota have ventured back into the affordable rwd sportscar arena with just a toe in the water(to keep costs down) and now that the demand has gone crazy they will develop faster models as they now they have a market for these types of cars.
Personally i'd like them to make a new supra! sort of a ssuccessor to the 2000gt, bit more wheel base and width than the 86 with a cammed aurion 3.5 V6, challenge the 350z, porsche cayman etc starting price around the 60k mark.