I bought mine from the dealer with 1074 miles on it. It was the exact color and options package as the one I ordered through the same dealership (was supposed to wait until June to get delivery). It was gently used, and had no stains on the carpet, upholstery, etc. When I decided to take the car, I sent them a list of things they had to do, including changing the oil, oil filter, air filter, etc. I had them rotate and balance the wheels and suspension, I also had them do a full checkup on the car, and also had them remove that stupid-ass dealership identifcation sticker on the back so I didn't have to ride around being an advertisement. The only thing I found that the dealership wouldn't do is inflate the tires to 42F/40R, which was easy enough to take care of after rolling it off the lot. In addition, my dealer did knock about 1000 dollars off the cost, and they were already beating everyone else in the state on the price of the one I had ordered.
So far, I have had it since mid-January, and just passed 6161 miles this afternoon. I just finished a three-week roadtrip and the car is a joy to own and drive. I have had only one problem, at the end of my road-trip, involving a bit of water and an electrical connector (mentioned in another thread) which, I'm told by the technicians at a different toyota dealership, is a problem Toyota is working on at the moment.
In all, I'd say that going the route of getting the fleet model at around 1000 miles isn't bad, but I would insist on the price being lowered, making sure that I got a good look at it (I was offered some kind of scuzzy fleet models by other dealerships without a discount that I certainly wouldn't have bought even if they were discounted), and making sure that it had new oil, filters, etc, was checked out before I picked it up, etc.
The cars themselves seem to be pretty darn solid. The technicians I spoke to when my car was in the shop were really surprized to see one in the shop because people have so fer problems with them.