I test drove the 06 sedan today. Looking for a new car for the lady, and test drove an 04 ex. then saw some pricing on the 06's and figured we'd take one of those for a test drive while we were there. (no 05's left in stock at all) Well, if the si is a hopped up version of what we drove today, it should be sick. She's dead set on the 06 ex now, and if I can pull it off in december and there are some available (doubtful though) I'd probably buy one too.
Good luck!
Edit for a fun fact: 30mpg city 40mpg highway, 140hp...when currently spending almost $700/month on gas, the lady will almost have the car pay for itself in saved gas money considering she's getting about 22-24 mpg on the highway in her piggish v6passat. (she drives around 120 miles a day for work) (I'm not even sure if the numbers work out completely, but hell, that's some dough, and its not even a hybrid!)