Here’s the skinny on Dashboard in the current version of OS X:
Dashboard is a collection of small programs, called “widgets,” that let you quickly do a wide variety of tasks such as checking stock prices, finding weather information, and more.
Note: You can also use widgets in Today view in Notification Center. For more information, see Use Notification Center.
That’s followed by directions on how to turn Dashboard on. I think it’s the end of the road for this part of the OS.