JetBrains released first stable of JetGroovy in silence. It's a good plugin for Goorvy. Also many thanks to JetBrains for nice contribution to Groovy.
You can get first stable version of JetGroovy here.
Thanks Graeme for this information.
Update: JetBrains has just updated JetGroovy. You can get the latest version at above link. But note that it requires Selena build 7038 or later. And they also blog about it. JetGroovy looks very nice :-)
One more information, seems IntelliJ IDEA 7.0 will be delayed to early 2008.
Update: JetGroovy 0.1 now is available on IntelliJ IDEA's plugin repository server and you can install it via Plugin Manager.