To be one of the first to order a copy sign up for free BSi newsletters at http://www.bsigroup.com/upload/Standards%20&%20Publications/newsletters/general_signup.html.
For a synopsis of the key changes and how they affect you, visit this news page again shortly after the standard is released. You can order the new standard when it becomes available online direct from BSi or if you are a member the UK Fire Association at a significantly discounted rate. Other trade associations may also offer this service.