a. One Copy per Device. You may install one copy of the software on one device. That device is the "licensed device."
b. Licensed Device. You may only use one copy of the software on the licensed device at a time.
c. Portable Device. You may install another copy of the software on a portable device for use by the single primary user of the licensed device.
from http://www.theage.com.au/technology/technology-news/does-you...
The original australian article states two non-definitive answers:
A: "A perpetual license of Office 2013 can only be installed on one personal computer. This means that the customer can only install it on one device, either a desktop or laptop, but not both. If the customer has a system crash, they are allowed to reinstall Office on that same computer. If there are problems with this process, customers can contact Microsoft technical support"
B: "No, the customer cannot transfer the license from one PC to another PC."
I would bet on A and and a confused PR department. Of cause if you wan't to report some kind of "news" you would root for B rather than investigate further.