this is from documentation.
As Far As I Know It Isnt. Probably Just For The Beta Testers… Or Is It? 
i found this page via google. i searched “unity 2d physics”. this page is public. beta tester resources are private.
Well i dont have access to it, so guess no.
@atmuc Oh, Didn’t Know. Maybe That Means There Getting Ready For The Release?
Possibly.
Also… users generally find it annoying when someone Types Like This With All Caps. It isn’t needed. Thanks. 
It probably just slipped.
It will be available along with the new 2D framework when 4.3 is released, which will be fairly soon.
we do
I think 4.3 is going to come out real soon 
I really hope so. I mainly do 2D projects, if not only 2D projects, if it’s as good as advertised in the forums. I’m glad though that they’ve getting this natively. What I don’t look forward to is using Mecanim. Not that I don’t have high hopes, just high expectations. Also I can’t wait but I hope it’s work it.
Good job for working on this Unity3D Technologies.
4.3 shipped 10 minutes ago.