not sure what you mean about the "dearth of info on the hot a4".
i'm in discussions with my dealer about the rs4, and expect to see it in new zealand in the winter of 1997 (july timeframes). the dealer is firming up specs and prices for me.
audi seem to want the rs4 to top the m3 (euro model). hence the change in hp for the car.
again, there seems to be no intention to put the tt in anything other than the rs models, to keep the line as a puka motorsports one (again similiar to bmw who have kept the marvellous m3 engine unique to that car).
there may be a s4 which would be a a4 quattro with the 30valve 2.8 v6 and sports suspension etc.
i'll keep the list posted on what i find out.