It won't work because the new iPad uses 4G LTE (700, 2100 MHz) bandwidth.
In Hong Kong, 4G LTE will be using the 800, 1800, 2300 and 2600 MHz band later in the year if I remembered correctly.
So sure, you can use 3G, 3.5G here... but LTE will not be supported.
Well, yes, but who would care about the 4G LTE when you can use the faster and cheaper 3G (wich is classed also as 4G in Hong Kong) conections? The LTE in the US is neccecary because the networks are simply so bad, that its the only way to have half decent thruput. But even LTE in the US is not coming up to half the speed of regular HDSPA conections in Hong Kong or elsewhere.