Along with Boris Johnson and Nigel Farage, they two most interesting politicians in Britain, I back Brexit.
I think Johnson is right that a British exit would not be all that disruptive, but would probably end with a free trade deal that omitted all the political ties which interfere with British sovereignty. Free trade with Britain is just in everyone's interest in the rest of Europe.
Furthermore, I think the British people will in fact vote to leave. Currently, polls show them almost evenly split, with perhaps a slight preference for the no side—i.e., for staying in. However, the referendum looks to me like the same sort of opportunity to thumb ones nose at the ruling elite as is manifested in the US in the candidacies of Donald Trump and Bernie Sanders. Not to mention the Tea Party a few years ago. This is a world-wide tendency; it is of a piece, if far more muted due to circumstances, as the Arab Spring, It is driven by technology: Web 2.0, social media, the growing lack of any need for control from above by a ruling elite.
I have long hoped the UK would leave the EU and instead join NAFTA. We are brothers over here; he fit would just be a lot more natural. A union of the Anglosphere also makes sense in terms of preserving our geopolitical interests. One hopes Ireland, Australia, and New Zealand would also soon come on board.
I hope the US and Canada are working behind the scenes to set this all in motion should the referendum go against Europe.