It appears that the latest update to the r22 SDK release moved aapt and the lib jar from the platform-tools to the build-tools directory. While we wait for JetBrains to release an update, here’s a quick fix using a couple of symbolic links:
From your AndroidSDK/platform-tools directory, run the following:
ln -s ../build-tools/17.0.0/aapt aapt
ln -s ../build-tools/17.0.0/lib lib
…and IntelliJ should be able to compile as normal.