What was true under Windows Vista and Windows XP is also true under Windows 7: With the prompt, many tasks can be performed faster and easier, because a single command is often enough, which would otherwise require dozens of mouse clicks.
Just calling the desired folder via the prompt is a bunch of typing work, but you can save yourself: Just hold down the [Shift] key while right-clicking on a folder in Windows Explorer. This will show you the “Open Command Prompt Here” command, which you can select with the left mouse button. Now the prompt opens with the folder you selected.