So why January 6th? Because that's the official launch date of the Mac App Store and it's unlikely that Apple would launch a Mac App Store without having a few new, shiny Apple-branded apps that appeal to a lot of people to kick things off. Plus ever since Apple previewed the Mac App Store back in October, the iWork apps have featured in all the official mock-ups of the store front.
iWork '09, the latest version of the software suite, was released on January 6, 2009. Nice coincidence, huh?