Personally, I don't see it having a dramatic impact on the resale value of the pre-07 models. For one, the paint jobs are not as complex, though they might look better in person than the pictures indicate. Also, the 103 motor is fully capable of making the same power, with a few tweaks here and there, and most people end up tweaking in the long run. The 6 speed is nice, but not a deal breaker for most folks, as it only becomes a real factor at above the legal, or practical, speed limits anyway. Mine cruises fine at 80MPH in 5th. The pre 07 bikes are some beautiful machines, and will hold their own, in my opinion. The same thing was probably asked/wondered about when the Ultra came out last year, and how it would effect the value of the 04/05 SEEG's, and I still see most of them selling for about what the MSRP was new. The SERK's like you have, from what I've seen in the local dealers around B'ham, are also holding their own.
The 07's are going to be great, and I look forward to seeing and reading about them, but I just don't see anything about them which blows away everything that came before. These bikes are hard to come by, and as long as the MOCO does not put them out in numbers greater than the past, they're all going to hold value, and be sought after machines. Just look at how difficult it is to find one now...