The RSM here in NZ allows for an operating frequency of 915-928 MHz for short range devices (Link). US / Canada Z-Wave kit operates at 908.42 MHz which is outside of the fair use spectrum block.
I had a friend who got a visit from the RSM about operating a Smartthings Hub and US Z-Wave kit he imported off Amazon due to the fact it can (and does - I'm told) interfere with several services - the RSM did manage to track him down successfully and give him a warning and told him to cease use of the equipment.
If you're either using imported Z-Wave kit, or are thinking of it then I suggest you switch this off and / or reconsider your options. Unless if this kit works on NZ's Z-Wave frequency of 921.4 MHz (or within the "fair use" block) then you're in breach of RSM.
Just thought I'd give this warning. While the Smartthings hub sounds awesome it isn't worth a warning / fine. Even though you can operate the Smartthings hub with Z-Wave turned off as it still contains a transmitter that is not operating in the licensed frequencies it is still a breach - this is a software switch, it may still transmit.
Edit: Changed since Australia has a SmartThings hub you can now use: https://www.geekzone.co.nz/forums.asp?forumid=73&topicid=250986