Sony MicroMV is actually an MPEG-2 Transport Stream (MPEG2-TS) that follows the IEC 61883-4 specification for MPEG over 1394 (sister specification to the DV over 1394 spec IEC 61883-2). I have experience working with MPEG2-TS over 1394 with a HDTV settop box. Even though I do not have MicroMV, after some collaboration with code and data samples, we determined that MicroMV is just MPEG2-TS and wrote a little program to capture it (see file attachment below). Instructions for compiling are in the comment header of the C program.
The output can be converted using the ts2ps utility from the DVB tools project.
The output can played by mplayer or maybe even edited by Cinelerra.
According to the first succesful user/hacker, Julien Gaulmin, it appears that something flags the start of a new scene and files should be split at that point. This seems to cause some problems for mplayer. We are not sure how to detect this at the moment.
UPDATE: Julien Gaulmin informs us that VideoLAN client, vlc, can read these capture files directly. Older versions may need the option --input ts. vlc can read from stdin and mpg1394grab writes to stdout for online preview!