There is a new A3 model due next year - which probably means like VW and the Golf - it will be another 9+ months until they bring out their sports model. My Audi dealer told me the first part of that!
I test drove the S3 a few weeks ago, and was dead keen on getting one. To be honest, I don't think its that nice a looking car, but the power and 4wd swayed me. I'm still waiting for my written off ED30 to get sorted, so I'm still holding off just now... until I saw the Scirocco R in the magazines - and immediately put a deposit down on one!!
I also drove a TTS - which was more fun that the S3, and the Golf GTI mk6 which was also decent enough.
If you read the mk6 opinions, you'll see that most people agree that there isn't much between the mk5 v mk6... or certainly enough to upgrade just now.