We've already seen how iPhone OS 4 now includes double-tap to launch the fast-app switcher for multitasking, and how you can now swipe left to get audio control widgets for the iPhone, but it seems those audio controls are working for iTunes streaming now as well - and maybe more?
Likewise, I've mention how iTunes streaming audio is working incredibly well under iPhone OS 4, and the widget controls make it even better. Which led me to think -- if iPhone OS 4 can swap out the iPod app for the iTunes app when it's using the new background music API, could this be the way iPhone OS 4 also shows you other streaming music apps like Pandora and Slacker? Instead of iPod or iTunes, the Slacker or Pandora app would be shown to the right, and the widget controls would let you play, pause, etc. those apps?
Makes sense to me, but we'll find out for sure on Monday.