Help!!We need a ActionInterval Like this...

it can be used like this:

function setScore(newScore){
  this.scoreLabel.runAction(
    cc.ActionWeNeed.create(0.3,  //time
      this.score,                //startValue
      newScore,                  // targetValue
      cc.ActionCallFuncWeNeed.create(function(value){  //call back with a float param(or double?)
                                                       // this call back run in update of the action.
        this.score = Math.round(value);
        this.scoreLabel.setString(value + "");
      },this)// with owner this
  );
}

it can also be used to change size of scale9sprite by runaction and any other scene~
as\ you\ see,\ we\ can\ do\ much\ more\ thing\ in\ runAction
~
will cocos2dx team add such a new actionInterval?

Not a bad suggestion, I have looks at a similar problem, but to overcome, I wrote some Native/JSB Classes to do specifically what I needed.

I like the Idea of your solution that lets you Inject your required function to run on every Interval update.