I moved your post to general discussion so you'll get a bit more action.
As for being able to tell if the boat has been winterized that's a tough one. If the dealership was messy, you may see a bit of antifreeze dripping out of the end of the pump, but that's about it. The problem is winterizing is mainly for the internal parts of the engine and the fuel system, so it's kind of tough to tell. The only real way to know if it's been fogged, or has antifreeze in the exhaust would be to run it for a bit, and at that point you would have to re-winterize it.
If it were me I would just go ahead and winterize it myself just for piece of mind. This has the added advantage of giving you first hand knowledge about your boat as well and the confidence to try other maintenance work. here's a thread that will give you the information you kneed to winterize it.
http://www.seadooforum.com/showthread.php?t=9132
Aaron:cheers: