The single license agreement states that you are limited to a single computer. The only exception is that you are allowed to install LabVIEW on a single computer at home provided you use it for work related purposes. That's my interpretation of the agreement. I believe the license agreement is somewhere on NI's site but I don't know where.
The current version does not have either a hardware or software key. The next version will have a software key. Before you install it, you will need to request a key from NI. The key will be tied somehow (MAC address, hard disk id, or something) to a specific computer.