As people keep saying the schedule is currently to keep the existing pattern, 3.X patches should be every 3 months, which atm that puts us at about the 2 year anniversary for 3.1. However, having experienced 2.0 launch, which ended up being 6 months from launch to 2.1. I suspect they are better prepared this time, but expecting this to be flawless would just be silly. So I'd say 3.1 would be the end of september at the latest.