Never really used this feature until today, but I'm completely cleaning off my homescreens and starting over.
Activities shortcuts are awesome. I came from BB land after many years there and one of the biggest things I missed were one touch shortcuts, like hitting B for browser or M for messages. The Quick Launch choices on the dpro are nice, but they require two presses at the same time and only launch apps, not activities.
Here's a great example - I wanted one touch to compose a new text message, so I added a shortcut activity to compose. Now with one touch, I can compose a new text. Looks like you can do this with just about any activity you want, so it's a great replacement to the BB home key shortcuts.
Anyhow, I've had my DPro for almost a month and never even looked at these, so I hope some people reading may discover these and how great they are.