Here's the maintenance policy: http://weblog.rubyonrails.org/2013/2/24/maintenance-policy-f...
Tl;dr: after 4.0 is released, no. But bugfixes have been merged into 3-2-stable that there should be a 3.2.14 before the security-only releases start.
Tl;dr: after 4.0 is released, no. But bugfixes have been merged into 3-2-stable that there should be a 3.2.14 before the security-only releases start.
Another big one is the 'not deprecating something in z releases (of x.y.z)' policy, which should help too.
Remember, Rails does not follow SemVer, so if you're expecting interface compatibility to line up with it exactly, you're gonna have a bad time. If we _had_ followed SemVer, you wouldn't see all those comments upthread about how this was 'the smoothest major upgrade ever', since in SemVer 3 -> 4 would mean no compatibility.