Thursday January 6th, 2011.
Mac App Store is scheduled to open today. Some sites are reporting that the Mac App Store will open at 12:00 PM Eastern Time or 5:00 PM UTC. As the zero hour draws near, it is unclear if Mac OS X 10.6.6 would be a required prerequisite for Macs to access the Mac App Store. According to some reports, Apple seeded Mac OS X 10.6.6 build 10J537 to Developers back in December 2nd, 2010.
We will see if Mac App Store requires Mac OS X 10.6.6 in 4 hours and 13 minutes from this original post time.