Apple just publicly released iOS 5, check your fresh install of iTunes 10.5 (which was released yesterday and is necessary for the update). Then you can update OS X Lion to 10.7.2 to get yourself some iCloud support. Check your Mac’s Software Update for the updates.
But before that, check for the iOS update on your 2nd gen Apple TV, which is out too.
After you’re done with all that jazz, you’re free to update to iPhoto 9.2 or Aperture 3.2 to see the photos that you shot and have been uploaded to iCloud while you were installing the 10.7.2 update. 🙂