In CS6 on a Mac, my source monitor is showing 2 channels for my audio, though when I click and drag audio only button to the timeline, it is only taking one of the 2 audio tracks. Why is this? I can drag it again to get a second track, though why does it not bring both at the same time?
PP treats stereo channels as one track.
So after bringing audio into your sequence, how can you later tell if an audio clip is mono or stereo? By loading it back into the Source Monitor?
You can tell by looking at the speaker icons in the track header. You'll see one for mono tracks, and two for stereo tracks.
You can also tell by looking at the waveform. Mono will show one, stereo will show two.