The light coming on is Toyotas way of telling you an oil change is coming up. There is a reset procedure in the manual, I don't recall it off the top of my head though.
The light will flash for x number of times 4,500 miles after last reset and be on all the time 5k miles after last reset
Off course while Toyota is still paying for your scheduled maintenance you may just want to take it in and enjoy they dealers coffee, cookies and generally annoy them with questions they don't know the answer to. :bravo: :boxer:
just had mine last week, came on at about 4900, it is the first service interval. no oil change, just rotate the tires and multipoint inspection and of course they reset the light for you. I am in a new area so it gave me a chance to check out the local dealer.