Microsoft, at least, collects more information. You get reactivation notices when you change a few things, doesn't have to be motherboard. Usually they will go through and a new signature is made, but if you keep doing it, they will eventually cut you off. Unless you have registered to a MS account, then you can keep re-using it as far as I know.
In the world of software licensing, MAC address and annoyingly hard drives are used quite often. Some software is non-transferable, and you end up having to call up companies and tell them directly of drive or board failure to get a replacement software key (They are usually quite stingy, seems like they are stuck in the past). Assuming you don't have a physical license key or license server instead.
As they say, legitimate businesses will pay to keep from getting audited and penalized, less scrupulous people won't pay in the first place. So their DRM really only harms their valid customers. The age old debate.
I would not put it past some malicious software to send out your MAC address and things to build up a library of potential targets. And I'm sure there are applications out there that politely ask you to send everything to some database when you click through the license agreement. All those data mining companies get it from somewhere.