The problem with hotels in Sydney with views of the fireworks is that they are
a) expensive
b) require a long stay
c) booked way in advance

As an alternatively, I would recommend a NYE dinner cruise with Captain Cook. You get a 5-course dinner waiter service and depending on the price of your ticket, all the bubbly and wine you can drink included in the price. The dinner cruise goes around the harbour while you eat and forms part of the parade of lit ships/boats that circle the habour between the "childrens fireworks" at 9pm and the main fireworks at midnight; i.e. you are part of the light show that everyone on the banks of the bay watch. There is a band on each of the 3 levels to entertain you while you dine. Just prior to midnight, all the boats stop in the middle of the habour so you get an unobstructed view (except for possible fireworks smoke that could obscure your view) of 3 sets of simultaneous fireworks - there are about 5 sets of simultaneous fireworks all along the bay. The boats are also directly in front of Sydney Habour bridge which has its own set of fireworks so you cannot fault the view. You can however be a bit close to the fireworks smoke.

My personal experience last year was fantastic. It was a brilliant atmosphere on board, the service was great and the view could not be more amazing. There is no josling with other people, sitting around bored in the cool night air, alcohol on tap, entertainment (swing band on the top deck and cabaret bands on the other decks), dance floor and a full tummy.

Last year, the ticket price ranged from A$350-A$500 depending if you want a higher deck or a window/middle table. The top level deck offers complimentary drinks inclusive of spirits and additional bubbly prior to midnight to toast the New Year in. The boat sails at 7pm and returns at 1am.

OK the price may be expensive but when you factor in the cost of a hotel of a decently located hotel with a minimum stay, this is a much cheaper option.

You just have to ensure you can get to the pier in time as all the train stations would have shut by then. Unless you are in a hotel in the area, it will be a bit of a walk and battle the crowds.

Not sure what is currently available but last year , a couple at a table for 2 next to us (we had a window table so they had a middle table) manage to purchase their ticket on the 30th Dec. We did purchase our ticket for a top deck window table (for 2) around May time. The Aussie company were good enough to post to tickets to us in London by recorded delivery for free.