Wondering about that, couldnt find anything concrete! I was using the rom in my evo and loved it, just swithed to CM because of the bluetooth HID stack!
I just paired my wiimote with my incredible using the latest cm6 kernel and set it up with Wiimote Controller from Market. I can confirm MIUI is not preventing it from working in any way.
Try a different kernel.
Sent from my ADR6300 using the miui-dev.com Forums App