Before describing the new feature let us first understand What are AutoCAD Grips?.
When you select the AutoCAD object without giving any commands it shows the blue square. These blue square are called as Grips (Shown in following image). If you don't want these blue square you can cancel these blue square by pressing ESC.
Now coming back to AutoCAD 2012. In AutoCAD 2012 when you take your cursor over these Grips it shows the shortcut menu from which you can select different relative available options. For example if you select line then it will show Lengthen / Stretch option. Same case is with other objects. As per the object selected relative options are available. This has been shown beautifully by Heidi Hewett in following Video.