McAfee, Symantec Think Vista Unfair: Update

A follow up to this post. It looks like Microsoft has done an about-face, and will allow kernel level access in Vista. From the article:
Microsoft Now Decides to Accept Outside Security for Vista
Until now, Microsoft had planned to block those companies from installing their products in the deepest levels of the new operating system, which is scheduled for release early next year.
Microsoft's shift means that users would continue to have a choice in the programs they use to protect their computers and not be tied to something that Microsoft offers.
I'd guess that Microsoft was just testing the water here, seeing what they could get away with. While the advertisement of their security and anti-virus products at system boot seems way over the top, denying kernel level access is much more reasonable (once again, as long as all of their products also play by those same rules). What is Symantec and McAfee going to do if Microsoft is ever able to create an OS that is reasonably secure? Why is it that some anti-virus vendors had absolutely no problem with this? In the end, Microsoft probably lost two close allies and business partners here, but in the short term neither McAfee or Symantec can do much damage to Microsoft. In the long run though, the gradual erosion of application vendors will be a devastating loss for Microsoft. One of the real and legitimate knocks on Linux is the lack of application support. As Microsoft slowly assails on nearly every business parter (and even channel partner) it has, more and more vendors will be looking to move to an alternative stack. Linux is ready and waiting.
–jeremy
Microsoft, MSFT, Vista, McAfee, Symantec, Linux