Containers, and I'm betting an Edit box would start to come in handy pretty soon.
Also, I haven't checked if you've added the array access expression, but would it be possible to allow it to be able run variables as arrays?
In CC you can place arrays in variables, but if you were to try to do something like sprite.value("myarray") loopindex, it wont work. That coupled with a way to set delimiters, and local variables, or instance variables would be incredibly powerful.