Joining the crowd

I've been a hybrid driver for the last five years, driving a 2007 Civic Hybrid. It's been great when the conditions are just perfect (wind in the back, flat road, warm weather), but mileage quickly drops if any of these are not there. And I drive a lot of hills daily. So I've always looked at Prius as the ultimately refined hybrid. Plus it helps that there is a very large and active community here, so after listening to whatdrives podcasts, reading the posts and test driving, we've finally put a deposit on a Blizzard Pearl 2012 III with a solar roof. Pretty excited to get it, though have to wail till the end of March till it arrives here. HCHII stays in the family, replacing an old Bonneville. So our average mileage (a CAFE number for families, anyone?) should hover somewhere north of 45+ mpg With my HCHII driving style, I am thinking I can easily get high 50s on a Prius.
So now on to making a list of must have accessories. Car is coming with rear bumper applique and carpet mats as the configuration they had it i.