Well, I'll be darned! I honestly didn't think this was ever going to happen, but Apple have finally added X-Trans RAW support for Aperture (and iPhoto). The latest camera RAW update just popped up in Mountain Lion's software update panel. I'm downloading it now, and once I have a chance to play around with it, I'll write a full report, but it's great news for Fuji users who like Aperture.
More to come!