Sony have played a blinder with the FS7 by adding the Multi-Interface shoe at the front of the camcorders handle. This has allowed Sony to add 4 Channels of sound to the camera with v2 FW upgrade due out this month. I have been waiting for this adapter for over 6 weeks for my A7s, hopefully it will come this week.
Support for 4-channel Audio Input and Recording
The FS7 supports 4-channel audio input. In applications such as an interview, this function enables the simultaneous use of an external microphone for recording ambient sounds, the built-in microphone for voice memos by the operator, and two optional UWP Series wireless microphones for voice of interviewer and interviewee.
In addition, the use of optional XLR adapter XLR-K1M or XLR-K2M provides additional 2 XLR inputs to further expand the range of possible applications.
The only downside to this arrangement is the inability to mount a camera top light, if only Sony had added a shoe onto the XLR-K2M adapter.