The Guardian's Patrick Wintour reckons Northern Ireland Secretary Peter Hain is leading the race for Labour's deputy leadership. Mike Smithson on PoliticalBetting.com is a tad sceptical, repeatedly highlighting Hain's young liberal background.
For my part, I reckon all speculation about the deputy leadership depends entirely on whether the two elections come off at the same time, because what happens in the deputy leadership election will inevitably be determined by what happens in the leadership election.
If Gordon is the only serious candidate - McDonnell is not serious and may not even get the required number of nominations - then we may indeed see the kind of wide-ranging contest for deputy that most are anticipating.
But if Gordon is challenged, either from the Blairite right or the sensible/soft left, then it's a whole new ball game. We will then be into pacts, deals, running mates and the rest, with the candidates seeking to demonstrate that they can unite the party by running on a balanced ticket
So far as I can judge - and in politics as in backgammon there is always the possibility of a late run - Labour's next leader and deputy leader are going to come from some or other combination of a dozen people.
Not all will stand, of course, but the potential runners are: Gordon Brown, John Reid, Peter Hain, Jack Straw, Alan Milburn, Alan Johnson, David Miliband, Hilary Benn, John Hutton, Hazel Blears, Harriet Harman, and John Denham.
Of these, Brown, Reid and Milburn will only the contest the leadership, while, in my judgement, Hain, Miliband, Blears and Harman will only consider contesting the deputy leadership,
The other five - Straw, Johnson, Benn, Hutton and Denham - could plausibly contest either post, but for reasons I shall explain, are more likely to end up as contenders for the deputy's job.
So the first question to answer, then, is will there be an "uber-Blairite" challenge to Gordon, and if so, who will it come from?
My hunch, for what it's worth, is that there will be. Brown has had to walk an incredibly difficult tightrope between outward loyalty to Blair and the desire to carve out his own agenda, and my guess is that eventually he'll fall off it.
In any case, such is the nature of politics that if Gordon is thought in any way to be beatable - and there are plenty of political pundits who think he is - then there is bound to be someone out there prepared to try their luck.
In my view Reid remains overwhelmingly the likeliest challenger, although Johnson might just run as the "English Candidate." I am certain that Milburn will dip his toe in the water, but may find his support somewhat lacking among MPs.
Let's for the sake of argument, then, assume it is Brown v Reid. Johnson will then be the big prize, the man with both the modernising credentials and the trade union links capable of delivering victory to either side.
If Brown can land him, he will have what looks like an unbeatable combination - a running mate who, like him, can authentically claim to be both New Labour and Real Labour.
If on the other hand Reid gets Johnson's backing, and all the other Blairites fall into line behind the Home Secretary, it will begin to look like a conspiracy to deny Brown the top job, and the Chancellor could end up looking isolated
Then again, this could work in Brown's favour, if Labour members as a whole decide that an obviously Blairite ticket would be incapable of uniting the party.
To me, the most intriguing possiblity is that the party ignores all talk of running mates and puts together a balanced ticket itself, as it did in 1994 when neither Prescott nor Beckett were officially aligned with Blair.
If so, then perhaps the most plausible potential deputy leadership contender in the frame is the one once described by the Brownites as the "when hell freezes over" candidate.
Almost alone of all the potential combinations, Gordon Brown as leader and Hazel Blears as deputy would give us a balance of Brown and Blairite, Male and Female, Scottish and English, Older and Younger.
Will it happen? I have no idea. But if it does - remember, you read it here first.