The new tyres needed will be noted by the dealer too, you'll pay for them anyhow...
Yesterday I was in a KTM showroom and I had a long look at a black 07 and 06 bike standing next to each other. Maybe I'm biased and this is very personal too but I really think the 05/06 bikes looks much better. This dealer said that, unfortunately, most people said the same.
The very angular lines of the 07 take some getting used to for me. The bigger fuel tank looks exactly that, MUCH bigger visually. Almost lumpy. In contrast to the fat tank the headlight-dash section looks weird, tiny and (too) small, especially from the riders view.
At this point it's unknown if the new fuel maps will work on 05/06 bikes. I do know that the part # of the ECU hasn't changed. If not, a PCIII, TuneBoy or Rapid Bike module can solve any fueling problems.
So my position stays the same, I'll wait for the next model SD probably due for 09 and skip the current face lifted model with a poor nose job...
R.