Well, I've no idea what's in it, because it hasn't happened yet. Couple of thoughts about what he needs to say though.
A lot of the comments about Ed's election, especially from the mainstream and right-wing press, have implied that the choice for Labour is to be either left-wing, and focused on redistribution and poverty, or electable, and therefore more pro-market and friendly to the middle-class. This is certainly the view of the world that informed 'New Labour' (which amusingly, now sounds 'old'). But does this dilemma really exist?
The interesting thing about Ed that gives me some hope is that he has clearly read and digested The Spirit Level. The whole point about Wilkinson and Pickett's argument is that there is not an exclusive choice between helping the poor and helping the middle class. Many of the things that trouble the middle-class (especially if we interpret 'middle' to mean people around the median income, rather than London-based people on six-figure salaries who know journalists personally) are precisely the result of poverty and inequality - crime and disorder, problems with schools, high house prices, unpleasant public transport and traffic queues. The trick is make it clear to people in the middle of the income distribution that they are better off too if the poor are less downtrodden.
Of course, this is not an easy trick to pull off. It is so easy to present things as binary choice - protect the interest of the poor, or protect the interests of everyone else. Particularly because the initial measures taken will appear to penalize the middle to no obvious gain for anyone except the poor (redistribution through tax and benefits, making schools more inclusive, restrictions on private traffic). So convincing people in the middle that we are all in this together requires a herculean political leadership, capable of developing a political rhetoric that 'mobilizes bias' (to use Schattschneider's term) around the kind of policies that the vast majority of people below the top 10-15% will benefit from.
Achieving this would be close to miraculous. But failure to attempt it would condemn us to alternation of Cameronite conservatism and Blairite-style government, and ever greater levels of popular frustration and apathy.