It CAN implement an ethernet connection over scsi, but not without a client-side driver. The driver provided is for X68000, not Macintosh.
That said, we've had a few discussions about this in the last day over in IRC...
There's some potential in this, but I don't believe it's in the direction most people are looking, as an alternate for SCSI2SD - I think TSE is a better alternate as far as feature parity goes.
In addition, max throughput as shown in the SCSI speed tests done using a RPi3 is around 1MiB/Sec... that's under half the throughput of the generally regarded "slow" SCSI2SD.
In addition, because the Pi needs to boot its entire Linux OS before it can run the software, it's not an "instant-on" device, that can simply be wired to a spare mole port, and boot a Mac when it powers up.
That said, I can see two very interesting uses for the device, CD-ROM drive emulation, and installation media procurement.
Because the Pi is a full-fledged computer on its own, running a simple jukebox frontend via lcd or similar should easily allow for raw CD-ROM images to be swapped. Of course, the speed of the virtual CD-ROM drive would be around AppleCD600-800 speed at best, but this should suffice for most classic games and software.
Alternately, a simple distribution package could be assembled that would allow one to boot the Pi, connect it to a powered down Mac with no os (or needing a re-load), and a simple curl script could fetch the most recent copy of a disk image (cd or hdd) for a user to boot off of to perform initial setup in the absence of the ability to create floppies/burn & boot CD-ROM of an installer. In addition, said image could be updated periodically, and as new images are created, the Pi "clients" would always fetch the newest version of the image.
