Alright, I paid $14 to get the key. But my PC is already activated using MSDN key. So the key received is valid to be used anytime in future or does it have any expiry date like 31st Jan 2013? I planned to do major hardware upgrade mid next year. So if MSDN key stopped working, I planned to use this key. Anyone has any idea?
If you actually paid for the key, I think it should work indefinitely (unless there was a fine print saying otherwise). You could even change your current activation to the new key if you so choose. You bought it, so why not?