Although these are not the best shots (sorry, even their camera was blurry), what you are seeing is a new option under Settings in Mango that allows the consumer to control if background services run or not.
In essence, when a 3rd party app insstalls with background services (say a "FriendFinder" app), it also adds itself to this section. The user can then simply and easily toggle on/off if that background service runs. This is good if battery life is going to be a big concern and you don't want that app periodically checking for updates or pushing data, or if you just don't want it running.
We also learned that the camera and mic can't run in the background, basically as a privacy issue--so no "spy apps" for now, although Microsoft seems flexible on this (they're soliciting feedback a lot from devs on these decisions).