Nikolai Mavrenkov already created a good description of the problem on Stack Overflow: http://stackoverflow.com/questions/36893449/textarea-placeholder-isnt-shown-in-ie-11-being-rendered-using-react

I just can confirm it breaks in IE11, but works in IE10 (and other browsers) with React v15.0.2.

AutoFocusUtils.focusDOMComponent,
            this
          );
        }
        break;
      case 'textarea':
        transaction.getReactMountReady().enqueue(
          textareaPostMount,
          this
        );
        if (props.autoFocus) {
          transaction.getReactMountReady().enqueue(
            AutoFocusUtils.focusDOMComponent,
            this
          );
        }
        break;
      case 'select':
        if (props.autoFocus) {
          transaction.getReactMountReady().enqueue(
            AutoFocusUtils.focusDOMComponent,
            this
          );
        }
        break;
      case 'button':
        if (props.autoFocus) {
          transaction.getReactMountReady().enqueue(
            AutoFocusUtils.focusDOMComponent,
            this