Far too early to say whether the protestors will achieve any of their desired objectives.  At the moment the camp is seen as a protest against unbridled capitalism.  I don't think that the protesters have detracted from this by occupying land next to St Pauls.  In a  way, such protests are simply a symptom of a problem, a bit like, say, civil rights protests in the US in the middle of the last century.  Each individial protest doesn't change the world, but as the movement gathers momentum and organisation, it becomes less and less easy to ignore it. 

So I woudn't say that the protesters have blown anything. If anything, the C of E's failure to support them, has given them much greater publicity than they would otherwise have had.  When the City of London   make their move to remove them, then that will generate more publicity.  By that time there will be more people disaffected with the system that keeps them poor while lining the pockets of the super rich - and the movement should grow as a result.