I like to think of prayer and God's plan more of a control issue.
God gave us free will, therefeore he's not often going to do something without our consent or our asking.
He's essentially tying his own hands behind his back to judge how holy his creation really is - if He spent all his time working miracles and plopping Jesuses down in every major city, of course we'd all be Christians.
Instead He gives us to choice to be righteous or non-righteous. Prayer is like a confirmation of that choice.
I guess; after all, I'm no theogist..