I dont own one yet (looking for an 07 model soon), but as I watched them over the past 8 years or so, my observations:
Subaru - it has its own nitch of followers, all of them very devoted regardless of outside opinions. The bug-eyed look attracted a few more folks in the 02-03 range (the STi helped that along). I had always thought it was very distinct and no one would ever confuse you for driving something as lame as the Chevy next to you (hurtful message intended, GM is committing slow suicide). That being said, after a couple boys came into my life (my sons), I had wanted something slightly more reserved and a little less "in your face" designing. The 06 fits that bill very well. With the 07 looking like a reserved 06 WRX from the outside, I can see exactly the crowd it will appeal to.
BTW, since 08 will see a Drastic change in Impreza styling and build, if you ever wanted an STi (or current WRX like I do), better reserve yours soon!