A note about shooting with two cameras: Your editor will need to sync the footage between the different views. To help them do this, clap your hands loudly in the view of both cameras right before you ask the first interview question … yes, just like an old fashion clapboard. Modern editing software has auto-sync features, but this loud clap will help you initially line up the clips.
Professional cameras, like DSLRs, give you fine control over the manual settings of shooting video and allow you to achieve the shallow depth of field (background out of focus) that people rave about. While they're primarily used for photography, DSLRs are incredibly small, work great in low light situations, and pair with a wide range of lenses — making them perfect for video. However, DSLRs do require some training (and additional purchases) of lenses.