Boris could just sit on the fence and keep his vote to himself.
On that we agree - why his view is especially important seems solely to do with in-fighting within the Tory party, which is of course the reason why we have this referendum in the first place.
We have a lame-duck PM presiding over a split cabinet, while at the same time saying the government position is 'stay in', and who hasn't the balls to get rid of the Eurosceptic faction within his own cabinet and where, it seems, Boris is more influential than our glorious PM - in appeasement terms it seems Dave is on a par with Neville.