All Honda has to do is create one V8 engine and supercharge it to fit it's models. One reason some people look at Honda(Acura) then at BMW is because of the Horsepower. Americans love power[especially horsepower]! 2.4L 160hp is not enough.
As for the RWD, Honda would eventually have to produce that platform. In saying that, switching to AWD will only make them have to price cars higher(say AWD TL is 35k RWD TL would only be 33k).
The smaller than MDX Luxury SUV is coming out in 07 named the RD-X, based off the 3rd generation CR-V(new Civic platform).