Microsoft has recently published a survey on Microsoft connect page, inviting limited number of software vendors in an event to help verify compatibility of third-party Anti-virus filter drivers with the next version of Windows. Earlier our friends at Softpedia has mentioned that Avast would be getting Windows 8 for testing this spring. We have also uncovered that Microsoft has started offering Windows 8 build 7971 to certain beta testers. So going by this invitation it seems that the Anti virus companies have already got access to certain Windows 8 builds.

Here is what the Microsoft Connect page reads-

Early Engagement Anti-Virus Filter Event

* Indicates a required field.

This event is by invitation only. It is open to a limited number of ISVs selected by Microsoft to help verify compatibility of third-party Anti-virus filter drivers with the next version of Windows. Before proceeding to complete this registration form, please note the following:

• Your company must receive an invitation email from Microsoft before completing this registration form. If you received an invitation, and your company is not listed under "Company Name" below, please contact fsfcomm[at]microsoft.com
• This event has been planned specifically for Anti-virus filter drivers. Registrations submitted for other types of filter drivers will not be accepted at this time
• Microsoft will plan to have a Filter Plugfest before the release of the next version of Windows. At Plugfest, we will extend the invitation to all Filter ISV companies, and will be able to support all classes of file systems filter drivers

Update: The page has been removed by Microsoft, though we have managed to get the screenshot of the page