This has been done. A good M6 car can brake the 12s with good tires and a above average driver.Sorry, i seem to be a little late to the party on this but i am actually fortunate enough to own a 2001 SS and a 2006 WRX TR.
when my SS was bone stock, it dyno'd 310 at the wheels and my personal best run was a 13.1 (while it was stock). I absolutely believe that a very good driver in the perfect conditions could run a 12.9. I can attest to the EVO slowness on the freeway as i have pulled away very easily many times in the SS.
You guys are also right about the fact that it would be very hard to find a stock T/A or SS at the street races that was unmodified. It is also very cheap to make those things 11 second monsters (think nitrous cause a lot of those guys do).
While i havnt taken my stock WRX to the drag strip, i think it would be very hard pressed to put up a contest at the drag strip against a T/A or SS of any kind. From what i have seen on here, i get the impression that a stock 06 could run low 14's and a stage 2 might be able to get into the 12's.
On another note, the WRX is hands down, the funnest car i have ever owned. (2003 SI, 1985 Omni GLHS, 2001 SS) It has all the power to beat 'most' stock cool-guy cars and has excellent handling. my factory warantee just ran out so i am hoping the cobb stage 2 with a stage 1 suspension puts this thing over the top and still maintains that daily driver capability that my SS lost after heavy modifications.