I think that the strength of import cars is in their aftermarket. I don't think we are going to see a whole lot of improvements in the base cars , but rather continued improvement in the aftermarket for them. But I think that that will lead to a constant battle between imports and domestics, I don't there will ever be a 'winner'. Domestics have great power stock, imports have great power after some work. And like hondamaniac said, that work is half the fun. I would much rather have an import and do all the work to make it faster myself than to buy a domestic, look at it and say, "wow, its done".
However, I do think that the base market for import cars will increase over the next few years. The WRX was a great addition to the market, adding some power to the selection. Now we have the Evo 8 coming out along with the new Rx8. It seems like every generation of cars has a model to appeal to the tuners, and I don't think it will come to a standstill any time soon.
But as far as which type of cars will have higher base HP, I think it will always be domestics. Until imports start dropping in V8s (not likely) domestics will reign in straight NA horsepower. Or at least until the Skyline makes it here!
