Recently Microsoft announced licensing terms for Windows Vista which made many users cringe -- your Vista license was essentially tied to a single machine. You could upgrade the machine -- some -- but the activation was pretty strict on how much you could change and how often.

Many users were understandably upset.  Microsoft was thinking of piracy while many hardware enthusiasts felt that they were being left out in the cold.  Many MANY users rebuild machines and don't want to pay hundreds of dollars for another copy of the OS.

Microsoft's new system is much more fair and, in my opinion, quite impressive in the technical work that had to be done to make the change on such short notice. 

With the new license, you can uninstall the software and install it on another device instead. But you can't have it on two machiens. That is what is nice about activation when it reaches its potential -- since it's "Calling home" upon installation, it can tell how many devices it is being put on and you can (one presumes) deactivate it on the previous machine.

This is similar to what users already see with products like iTunes where users can deauthorize a machine when they upgrade.

So hooray for Microsoft for this one thing.

Now, if they can listen to Robert McLaws suggestion that they make family upgrade pricing more affordable (so that a household with multiple computers can get multiple licenses very cheaply) then we'll be really talking (my household has 4 machines plus I have 2 laptops on top of it, would be nice to get a discount for those 6 machines that are only going to be used by 3 people).