Unfortunately, not for pinned items. However, if you want a menu of shortcuts you create placed on your taskbar, you can use text-based Toolbars.
Creating a Toolbar
Create a folder any where you like (your home folder most likely) and name it whatever you would like to appear on the taskbar e.g. "Design". Fill it with the shortcuts you would like to have appear in the pop-up menu.
Right-click the taskbar in Windows 7 and select Toolbars -> New toolbar...
A Selection dialogue should appear. Navigate to the folder you want to display on the toolbar ("Design") and press Select Folder
.
You should now have an item called "Design" with two small caret >>
arrows near the Windows notification area. Click the two small caret arrows to display a pop-up menu of the shortcuts you placed in the "Design" folder. You can do this with multiple folder (repeat steps 1-3) as well as placing sub-folder in these menus (e.g. a Design → Adobe sub-folder can hold all your Adobe-specific shortcuts).