Not Linus, not Stallman, not IBM, not Microsoft, not Novell, not SCO, not Red Hat. No one.
We (OSS developers) just have our personal reputations, a fleeting currency.
Stallman is definitely in the position of power, since most of the developers of the GPL software currently in Linux adhere to his anti-DRM philosophy, and are likely convert to GPL3 in order to advance that philosophy. IBM and others can attempt to combat that, but only if they are willing to take on the significant expenses of forking those products and maintaining them independently. I'm sure you're aware of how difficult that will actually be, especially with products Linux is completely dependent on such as gcc.