I think i'm with jockey on this one with regards to upgrades.
Also, on the subject of the activation system:
http://www.tagesprotection.com/Guide...structions.pdf
After giving it a quick look, it seems that you DON'T need to use up an extra activation if for some reason you need to format your hard drive.
The activation code can be stored in a file, so as long as your PC configuration hasn't been changed significantly in hardware or software you can just use the previous activation. The activation code is a hash value of your PC's components which, if i understand correctly, is just the result of an algorithm that looks up your PC components, assigns some numbers/IDs to them, does some math and extrapolates a final value in a way that's not possible for a third party to reverse and see what you actually have in your PC (ie, something like one-way encryption and comparison of the encrypted values).
As long as the components are the same, your hash string will be the same. So, if you format and reinstall your OS you can then install CoD again and when prompted to activate select the "i have already received my activation code" option. At that point you will be prompted to copy-paste it from the text file (that's what you should definitely save on some removable media device) and you will be using your original activation instead of using up a second one.
That's all according to how i understood the manual after a quick glance. Also, i don't know what they mean when they say "as long as there's no significant changes to your hardware or software". For software, i guess it means the OS type and nothing more (XP/Vista/7). As for hardware, it doesn't specify in depth. I guess it would definitely look up the type of CPU and/or motherboard as well as the GPU when calculating the hash string, but it would be overkill if it also took RAM and hard drives into account, as that would mean an extra wasted activation if you wanted to do some cheap RAM upgrade or your hard drive died and you installed a new one.
I guess we'll have to wait and see, but it's looking more user friendly than most of the other DRM we've seen lately.