The Scala IDE  developers write: "It's been a long journey! The Scala IDE for Eclipse has reached the first release candidate for version 2.0, and if no critical bugs are reported, this will be the 2.0 release! Thanks everyone for the patience and the tremendous work that got us here!
After the 2.0.0 release we will continue to support 2.0 with maintenance releases including important bug fixes. However, the focus will shift to the 2.1 development, and concentrate on the upcoming features. Also, 2.0.0 is the last version that supports the 2.8 compiler. This decision was not taken lightly, but the effort to support 2.8 is way too high and slows down development too much. We believe that the 2.0.0 release will be a good IDE for the few people that cannot upgrade to 2.9.1 in the short term (about 2% of our downloads).
Hence, we are happy to announce that the first Release Candidate (RC1) of the Eclipse IDE for Scala is ready for download!  This release comes in two flavors: the 2.9.1 version, and the 2.8.3-SNAPSHOT version.
The 2.8 compiler shipped with this version of the plugin is based on the development branch of 2.8.3, and is fully binary compatible with both 2.8.2 and 2.8.1. It contains the same improvements to the presentation compiler as the 2.9 version, and a number of bug fixes related to Java signatures. Also note that the 2.9.1 compiler shipped with this version of the plugin is fully binary compatile with both 2.9.0-1 and 2.9.0.
A list of fixed tickets for this release is available here:
You can install the new release by pointing Eclipse to the following update site:
for the 2.9.1 version: http://download.scala-ide.org/releases-29/stable/site 
for the 2.8.3-SNAPSHOT version: http://download.scala-ide.org/releases-28/stable/site 
Other releases can be found at:
Both plugins are ensured to work with Eclipse 3.6 (Helios), which is currently the officially supported Eclipse platform for the Scala IDE. Support for Eclipse 3.7 (Indigo) is experimental.
Happy Scala coding!
— The Eclipse Scala IDE Team