Instanceof for Map

Using the latest builds, I can't seem to be able to write:

if (body is Map) {
  …
}

Is this expected or a bug? The error says '2 type argument expected.

Nevermind. I found the answer here:

http://stackoverflow.com/questions/13154463/how-can-i-check-for-generic-type-in-kotlin

This does seem a little confusing however. Any chance that ‘is Map’ would ever be supported?