Microsoft has recently released Windows 8 Release Preview. This is much better version than the Consumer Preview, but still there are lots of questions, but time will tell. Anyway, you can download Windows 8 Release Preview directly from Microsoft site here.
I’ll post some updates and reviews on Windows 8 Release Preview. So come back soon 
I was wondering if you were able to get your X-SendFile ISAPI Filter working for IIS? If so, is it available for download and does it work on IIS 6?