I only needed a single bed so I didnt bother calling the hotel. Priceline only guarantees single bed, though if you are one of the first batches of people to arrive at the hotel to check in, you probably wont have trouble requesting a double. Though I've noticed some places are charging more now for doubles. I think Hotwire has an option to guarantee double beds. Also, The Palazzo/Venetion all have sofa beds so technically it's double bed I guess :)