I've received from email from an OpenYou reader who purchased the BP791IT, which is the updated version of the HEM790IT Blood Pressure Monitor from Omron.
They've verified that this blood pressure monitor does work with OpenYou's libomron library. So, go forth and purchase, knowing you can still pull your data off of the device on any platform libomron supports (which is anything libusb supports).
Please note that I've been getting a few issue reports with getting libomron working on OS X, having to do with the kexts not causing the device to detach from the HID Manager correctly on 10.6.7+. These reports have been rather intermittent, but if you experience any issues, please get in touch with me via email or file a bug report on the github site.