There will probably be fireworks at Lake Eola, I wouldn't try to find a restaurant without a reservation. There's really not all that much downtown in the evening that you would be able to jut walk up and be seated, especially on NYE.
Their fireworks show are the best on NYE. Downtown Orlando is not a good place. There is the old Church Street thing, but it is crowded and on NYE the streets are closed and you have to stand in the middle of the crowd! Not to mention that they are football wannabes waiting for the Bowl games! Not to even mention the noisy train tracks!
Thanks CAA1000, since you're from Orlando, you're the best to tell me what to do! I will follow your advice and stay at Disney! Maybe we will go at the Boardwalk and hope to see some fireworks!