The most recent version of m2eclipse is 0.12.1. This will be the last "Sonatype" m2eclipse release as we are moving the code to Eclipse Foundation and plan to make m2e part of Eclipse 3.7 (Indigo) release.
Below, you’ll find a list of changes in this most recent release. If you are looking for more detail, or if you would like to see release notes from earlier version, please see our archive of release notes on the m2eclipse Wiki.
New and Noteworthy Changes in 0.12.1 Release

What’s New and Noteworthy in this release?
Updated embedded Maven 3.0 - this release includes Maven 3.0.2.
Updated HTTP transport layer - this release includes updated HTTP transport layer based on JBoss Netty and Ning Async Http Client
New and Noteworthy Changes in 0.12.0 Release
Integrated with Maven 3.0 - this release includes Maven 3.0 (Final).
New HTTP transport layer - this release includes brand new HTTP transport layer based on JBoss Netty and Ning Async Http Client