To some, this question may seem a bit premature considering it's difficult enough for most of us to get our hands on one Wii Board let alone two but it's a question I've seen asked. Unfortunately, according to the info on the official UK Wii Fit site, only one Wii Balance Board can be synchronised with a Wii console at any one time so unfortunately it looks like no support for multiple Wii Balance Boards (yet?).