One advantage it has over Scala is that it doesn't do erasure of type parameters. I wonder how this works when it comes to interop with existing Java code though.
The other broad advantage seems to be that it's designed with a bit more restraint than Scala when it comes to the feature-set. Although personally I find all the Haskell-like implicits and the advanced type system stuff in Scala very interesting, I can see how this may end up holding back adoption by Java shops.
So: I'm reservedly interested in it, although does seem a bit vapourware at this stage.