Sure, the most recent official FAQ (along with inquires I made) suggests:
- 4 FP+ experiences per day, up from 3. (Original testing from 2012 allocated 4 FP+ experiences per day.)
- FP+ testing will continue. It seems the most recent limited test in June did not go particularly well.
- Only onsite guests with vacation packages will be "eligible" for FastPass+ while the system remains in test.
- Disney received strong negative feedback on the "groupings" offered for FP+ selections. It seems guests want to be able to pick whatever they want. Consequently, Disney may eliminate these. If these groupings are eliminated, I'm not sure how many will use FP+ selections for It's a Small World.
- FP+ experiences will be linked to tickets. For example, a 7-day ticket receives 7 days worth of FP+.
- Eventually DVC members will be eligible for FP+ but will need to link their tickets to their DVC point stays. Details to be announced (much?) later.
- No official word on how FP+ eventually will work for offsite guests. For now, they will only be able to use FP.
P.S. The last point has me wondering if WDW is considering keeping FP permanently for offsite guests.
Originally, FP+ was supposed to completely replace FP. Now, because of scalability issues, I'm wondering (can't find a source to confirm this one way or the other) whether Disney is considering making FP+ an onsite-only perk.