FYI and not that it would do most of us any good, but I just got info from a CM friend that they are doing CAST ONLY Space Mountain Previews today.
They are only during certain hours of the day (forgot which of the hours) til around 11pm tonight. Cast only and must be in costume with resort ID. They can go before or after their shift today or during their breaks. They announced the preview only today probably to avoid a mad rush.
edit: oh yea CMs were also asked to enter from backstage.