http://opam.ocaml.org/blog/opam-1-2-pin/
(How to pin a development is central to the day-to-day development workflow of OCaml/OPAM users and quite annoying to change after-the-fact, so we're eager for feedback on this iteration before we bake it into the 1.2.0 release).
The OPAM blog is only about 2 weeks old, so there'll are quite a few more posts coming up as our developers discover there's quite a lot to write about :)