Does the ScanSnap IX500 work with Ubuntu?

YES

This scanner does work with Ubuntu with sane/xsane out of the box.

Old backstory (when the ix500 was just released)

The SANE team got it working by hacking up a backend for the ix500. It currently only provides color scans at the driver level (gray and B&W are done in software). Pull down the sane-backend project from the git repo, compile it, and install. There may be a few permission problems, but as root, I can run simple-scan and get everything I want out of it.

This device prides itself on wireless however the wireless only works with Android and the iPhone, and to make matters even worse configuring the device to connect to the WiFi access point requires Windows or MacOS.

You won't get your full value out of this scanner with Linux. That's because Fujitsu doesn't fund or endorse the SANE project (their loss, and our loss). That said, it'll work to some degree.