By Nick Assinder
Political correspondent, BBC News website
Perhaps the oddest thing about Gordon Brown's expected rise to become British prime minister is the fact that so many claim to know so little about what he will do when he gets to 10 Downing Street.
On both policy and personality there are conflicting views about what, or who Gordon Brown really is.
Tony Blair is handing over to his long-time chancellor, Gordon Brown
He has lately attempted to open up on a personal level, even launching a bit of a charm offensive.
And he used the launch of his leadership campaign to offer some real insights into what he may have planned for the country when he walks into No 10, as expected, in a few weeks' time.
On a personal level, he is regularly caricatured as a private, introspective, moody and self-sufficient individual whose ideal team consists of just one and who, when crossed, bears a grudge.
That impression has not been helped by remarks from colleagues such as former Home Secretary Charles Clarke who spoke of his psychological issues and inability, or refusal, to work with others.
In an attempt to dispel some of that image, Mr Brown has undergone a voluntary makeover of late.
He has a near-permanent smile on his face, and has been ready and even eager to talk about his family life and personal tragedies, such as the loss of his first child - again referred to during his campaign launch.
Uncertainty remains over Gordon Brown's position on war
Still, many fear he might be an even less collegiate premier than Tony Blair - an impression he clearly wants to dispel during this campaign, with talk of listening to people's concerns.
Politically, there have also been conflicting impressions of where Mr Brown would lead.
Some claim he has an Old Labour heart beating within his chest, while others point out he was an architect of the New Labour project, along with Mr Blair and former minister Peter Mandelson.
However, he has now given some pretty clear indications of what Prime Minister Brown will do when he enters Downing Street, a decade after he first considered the move.
Most have expected he will have a big surprise or two up his sleeve to mark his first days in power - much as he did immediately after the 1997 election victory with the move to give the Bank of England independence from government - again something he recalled in his speech.
He hinted at the possibility of introducing a written constitution to underpin all that is best about the country's shared beliefs and values.
Brown's support for Trident nuclear weapons is controversial
Although he made it clear that, while his first big policy will be centred on restoring trust in politicians, a written constitution may be some way away.
He did, however, promise to make the government and ministers more accountable to parliament and boost MPs' engagement in the business of government.
He also confirmed he would introduce a new ministerial code to combat allegations of sleaze in the wake of ministerial resignations, dodgy dossiers, spin, attempts to bury bad news and the "cash-for-honours" affair that have peppered the past decade.
It is also thought he may bow to demands and create an independent body to oversee ministers' behaviour.
He has also pledged to give Parliament votes on going to war in future, and put devolving power to individuals and local institutions centre of his agenda - that will face a test with the Scottish Nationalist Party now the biggest in Scotland.
Controversially, he has already thrown his weight behind replacement of the Trident nuclear weapons system and the possibility of re-starting a nuclear-power programme.
He also repeated his pledge to create a government full of "all the talents", green, modernising and still New Labour.
That has seen suggestions he will follow the path he started as chancellor, by putting big issues out to inquiries by bodies of external experts, and bringing such specialists into Downing Street.
Questions remain over the chancellor's approach to the NHS
But there remain some big unknowns about where the chancellor stands on a number of key Blairite policies - specifically city academies, university tuition fees, and selection and streaming in education.
And he has already suggested a different approach to health service reform from the prime minister, with talk of running the NHS as an independent board.
None of those were answered with any great clarity.
Neither were questions over his support for the Iraq war, although he clearly signalled there now needed to be a shift of emphasis towards political reconciliation in the country.
What is now clearer than ever, however, is his style will be different, his Cabinet team will be different and there will undoubtedly be surprises aimed at reinvigorating Labour as it prepares to face the growing threat from David Cameron's Conservatives at the next General Election.