Apple has informed Mac Developers that demo, trial, and beta versions of software will not be permitted on the upcoming Mac App Store. Apple will only be accepting fully functional, retail versions of applications. Unlike with the iOS App Store, Apple is encouraging developers who wish to provide demos, trials, and betas to post them as files on their own personal websites.
Your website is the best place to provide demos, trial versions, or betas of your software for customers to explore. The apps you submit to be reviewed for the Mac App Store should be fully functional, retail versions of your apps.