A few days ago Scala 2.7.2 RC2 was released. One of the new features is mixed Java and Scala support in both the compiler and the Eclipse plugin. I decided to try it out. Installation was very simple. I then set off creating a simplistic Java class side by side with the Scala object, in the same package. I then created such a Java object in my Scala code, and ran it. It just works! 
Pity you can’t do it both ways.. if it’s possible some day it’ll be so sweet.