As recent news (Wired and CNet) indicates, Apple is using an Infineon TPM chip in order to bind its forthcoming x86-based version of Mac OS to particular hardware platforms (although the story is disputed, see here). The OSx86Project develops a version of Mac OS that can be run on any arbitrary x86 platform. This is just another example of how companies attempt to tie products and/or services together by technology. Apple is doing a similar thing with its iTunes service and the iPod player. There are many other examples.
Whether that's a valid strategy from an economic and legal point of view is a complex question. It's going to be interesting whether Apple will try to use the Digital Millennium Copyright Act against the OSx86Project.