Besides, I have never seen a company react quickly on a such a topic as for example bitcoins.
At the moment it is 'only' a geeky project with lots of people putting their spare time into. This is (not yet) something of true market value to, lets say, google.
Imagin how many people this corporation would need to involve with decisions until the intern gets his idead approved to build Google Mining Riggs TM.
An putting 'secret' code in their programs for distribution is a far shot aswell. Just look at other software which is suspected of doing things the user does not know of. This would be a huge image damage. Just look at M$ XP activation and how long people have been trying to find out what data is being send.
Just my humble opinion...