This is kind of a neat new feature in the IDE. A new window is available called the Code Definition View (Ctrl-Shift-D). This window can replace the functionality of pressing F12 when you want to see the definition of a method or class. When you open this window, any time you click on a class, method, or and instance of a class, the Code DefinitionView window will automatically bring up the definition. I would post a screen shot but unfortunately SharePoint doesn't support that.