The nightly has been failing for the past 7 days: https://jenkins.scala-ide.org:8496/jenkins/view/Scala%20IDE%202.1%20for%20Juno/job/scala-ide-juno-nightly-master-210/
So, the good news is that you are using the right update site :) I cc-ed Eric as he may have more insights
The Juno nightly is back!