You can, but I've been trying to capture footage I shot using two different microphones in two different channels, and I used the Sony Handicam to do it, only to discover that this little baby camera downmixes the two mono channels into one stereo channel, which means I can't edit them separately.
Unless there's something I've missed, it seems that this is the case because that little camera only records (and apparently outputs) in one stereo channel, which FCP5 reads as two identical mono channels.
When I use it to capture my 24A footage, for which I used the onboard mike in the left channel and a sennheiser lavalier in the right channel, I can monitor both channels in FCP5 discretely during playback and see their differing levels, but once I capture the tape into FCP5, the resulting QT file is downmixed to two identical mono tracks, each of which is a stereo downmix of the original two channels.
I'm going to keep at it, but I have a feeling it's because the Sony's camera audio chip is not equipped to record (therefore nor output) two separate mono channels.