Spring 3.1 is GA Today - Adds Java 7 Support, Environment Abstraction and ...
22.05.12
The original plan had been to provide completely Java-based configuration for the Spring container, but after quite a bit of experimentation with a first approach, and even going as far as a full milestone, we rethought it; it didn't quite meet all the design goals that we had. A full design iteration later, we landed on the current approach around @Enable* annotations.
We also had early support for Servlet 3.0 containers, and ran into problems with the implementations themselves. We had to do some iterations with the teams there, to make sure that the implementations were correct.
But really, the main reason was that we intentionally increased the scope to include Java 7 support in 3.1, instead of 3.2. That's around the fork/join support, JDBC 4.1. We also made the decision to support Hibernate 4 as early as possible, even prior to their final release. We're currently on their candidate release 7, and we have in fact shipped on that, so Spring 3.1.1 will immediately upgrade to Hibernate 4.0 final when it becomes available.
Source: InfoQ.com