I installed the just-released build #7523 and find that now the plug-in manager is showing IntelliLang in red and disabled with the tooltip text "Plugin is incompatible with current IntelliJ IDEA installation". The installed IntelliLang version is 2.1.5. Strangely, the IntelliLang shown in the "Available" tab is version 1.2.2. Also curious is the fact that according to http://plugins.intellij.net/plugin/?id=1105 IntelliLang 1.2.2 is the second-to-latest version that is compatible with IDEA 6.0.
Is this a mix-up in something about how this IDEA build identifies itself internally? (The About box shows 7.0 and all the other information appears correct.)