Paul Thurrott on iOS 5:

The Notification Center also provides a similar view on the lock screen, with each notification laid out vertically. Stealing a page from the Windows Mobile 6.5 playbook--not that many people would even notice this --you can also slide your finger across any notification, instead of the Slide to Unlock area, in order to go directly to that app after you've entered your PIN. Yep, Microsoft had that first.

I guess that happens once in while.