This interaction is already familiar to users from notifications and multi-tasking in ICS:
On iOS swipe has been used on app caller Reeder to mark items as read or star them. See video of Reeder app and how it uses swipes on lists here.
Swipe as gesture has few downsides. It is pretty difficult to discover and it is already reserved in tabbed UIs for moving between tabs. In any case, it's going to be interesting to see how this interaction gets used in apps. It is not going to be suitable for all apps but there definitely will be apps that could benefit from this.