Don't be surprised if Akai Katana pops up on Steam in the next year. Mushi did better than predicted, so I'm thinking it's likely Cave will be bringing the rest of their 360 archives over. That may actually save the emulation of the arcade boards entirely, though not in the way you're likely thinking.
It'll stop people from pestering the codemonkeys to the point they get annoyed and stop wanting to even look at the Cave stuff.