As for the Budget's general flavour, we'll probably get an idea of that today, too. Brown's currently giving a speech in which he's brushing over recent tremors in the markets, to say that we are "weathering the storm; now is no time to turn back". Which comes straight off the same old hymnsheet: let's stick to our current deficit reduction plan (such as it is), and turn up the spending taps this year. We'll probably be able to tell who has won the battle of wills between Numbers 10 and 11 by how many spending giveaways there are in the actual document.
But will it do Brown any good? Well, obviously, its going to be difficult for Labour to squeeze any positive headlines out of this. And Budgets have, historically, tended to encourage poll declines rather than boosts. But I suspect more will rest on the growth figures due out in April. According to the Guardian, "Ministers are increasingly optimistic ... that the figures will not reveal a slide back into recession." But, if that's not the case, then it could be one of those great crystallising moments: when everything that's gone before suddenly looks all so, so different.