i'm #2 at my dealership, and they sell plenty of cars, so i'm guessing i'll get one the first month... but lately i've been considering dropping my name back down to the bottom of the list and trying to buy myself a year or so to get my legacy paid down so maybe i can have both.
i think the best comparison as far as availabity is the s2000. it's produced in roughly the same numbers, it's about the same price, and i think americans' perception of honda is about in line with what they think of subaru (at least when you're trying to get them to shell out $30K+ for a car)... this is an enthusiast car and enthusiasts are picky, loyal, and indecisive. plenty of people might want it, but i doubt that many will actually put up the cash to drive one home.
i think the STi, like the s2000, will be easy to get a hold of after the initial blitz dies down. you can easily get an s2000 in most parts of the country, but the dealers still sell every one they get.