Groovy-Eclipse 2.5.1 includes Groovy 1.7.10 by default. Groovy 1.8.0 can be optionally installed. Groovy-Eclipse is installable on STS 2.7.0, Eclipse 3.7.0, 3.6.0, 3.6.1, or 3.6.2. There are different update sites for Groovy-Eclipse targeting Eclipse 3.6 and 3.7. See above for the update sites.
There have been 30 bug fixes in this release. You can see all of them in the Codehaus issue tracker.
We appreciate all community support and feedback. If you wish to join the discussion about Groovy-Eclipse then please sign up for the mailing list. For any issues you have (or enhancements you would like to see), please raise them in our issue tracker. If there is an existing bug fix or enhancement that you require are not seeing any movement on, please make some noise on it (and get your friends to do the same). We respond to community feedback, and we can make the most improvements to Groovy-Eclipse when we hear directly from the community. So, please speak up!