I have been to Ocean Park last week. It is very crowded, just like walking in Mong Kok. Since, this is a period of special event about Christmas in Ocean Park. Besides those original events such as Jelly Fish, Shark, Ocean Theatre, Giant Panda, Cable Car, the theme park also organized some other events like ice-skating show, Christmas Tree Lighting show, swinging miracle and Santa's cattage etc. However, such special events are provided until 1st Jan. :)
By the way, the theme park is providing more and more new stuff, you can see there are constructions work besides the park, there will be new facilities and hotels coming in the future.
The theme park also cooperates with Ngong Ping 360, purchasing ticket of Ocean Park with the used ticket of Ngong Ping 360 will receive a 10% discount, and vice versa.
Transport: CityBus Route 629 from Exit B, Admiralty MTR