Yes it is possible (IntelliJ IDEA 11.1.3 CE with Scala Plug-In 0.5.948, but this has been possible for a while).
You need to select the receiver not the method itself. For instance, assume dataDir is of type java.io.File. Then I can do
dataDir.listFiles().foreach( ... )
where foreach is available through implicit conversion from Array to ArrayOps, thus is underlined. If you select dataDir.listFiles() and choose from the menu Navigate -> Implicit Conversion (shortcut Ctrl-Q), a popup menu shows you all possible conversions, and selects the conversion currently applied.
