All four Walt Disney World theme parks are now offering passholder exclusive entrances. Look for giant red signs as you approach the park as they can be in different places (to the left at EPCOT and Magic Kingdom and to the right at the Studios).
The dedicated entrances are expected to remain throughout January 2017 and possibly be extended beyond that.
Back in the 90s, before construction started on California Adventure, Disneyland tried passholder only entrances. I found it was a rare occasion when the line was actually shorter than the main entrance. The problem in Anaheim was that all the passholders tended to arrive at the same time (after work mid-week, mid-morning on the weekends).
So far in Orlando the waits are generally less at the Passholder entrances. That’s in part due to cast members requiring you show your passholder card in order to get scanned.