If you wanted to go you could always rent a car for a day from the car care center - a shuttle will take you back & forth to your resort (if on property).
The public bus, WWW.GOLYNX.COM, has a stop at the TTC. You can go to their website to find out how many transfers may be needed to go to your destination.
Just my opinion but if it's not worth renting a car it's probably not worth going at all. Unless you're staying at a MK resort you'll have to take Disney transportation to a park (including DTD or MK), take a monorail or ferry to the TTC, take a Lynx bus and probably have to transfer at least once. Compare that with a 15 minute drive.