Bruce, this is a small item, but I believe the '08 comes with a fairlead on the roller furling cam cleat, but not the '07. It makes a big difference and you definitely should have it -- about $5 and available through Hobie or your local marine hardware.
Also, the new balanced sailing rudder was a running change during '07 -- easy to tell by the notch in front. I think that's a free upgrade also if not installed.
Oh yes, some of the pins (rudder pin, aka brace sheerbolt) were improved along the way -- good to replace with the latest available and keep the old as spares.