For many people, the jury is still out as to whether Shearer can cut it as Labour's leader. They bear no ill will towards him nor harbour any great expectations of him. He is seen as a Mr Nice Guy. There are no jagged edges for people to rub against and force them to form an opinion of him. They simply do not feel they know him. Consequently they have yet to be convinced he has the necessary goods to run the country.
In seeing off David Cunliffe, Shearer revealed hidden strengths in crisis management drawn from his days working for the United Nations. But it is arguable how much of that washed down to the electoral coalface.
However, anyone in Labour's ranks who might be fretting that Shearer will retreat into his shell now the threat to his leadership has dissipated need not worry.
He is utterly determined not to squander the advantage he gained at year's end which saw him not only squash what would have become a leadership putsch, but emerge from the tussle in a far stronger position as leader.
A noticeable rise in support for Labour in pre-Christmas polls and plaudits for the party's ambitious plan to build 100,000 "affordable" houses meant he ended 2012 on an unexpected high.
Entering the crucial mid-term year of the electoral cycle, Shearer knows he must maintain that momentum. To use a tired cliche, for want of something better, he has returned from his summer holiday not only "hitting the ground running", but with the intention of shaking up the political status quo by doing some things markedly differently.
He is breaking with tradition by deciding to make the annual pilgrimage to Ratana other than on the day normally reserved for delegations from political parties. In doing so, he is underlining behind-the-scenes efforts to rebuild what was once a special relationship between Labour and the Ratana church.
Shearer's desire to stir things up will see him bucking convention elsewhere in coming weeks. Still handicapped by a charisma deficiency and a lingering difficulty in delivering a crisp-sounding soundbite, he has to find other ways of stapling his presence onto the nation's consciousness.
He won't give details. But he is likely to take positions on issues which will capture public attention and with it widespread approval. He may take positions on some things Key may well wish he had adopted.
It does not mean Shearer is about to become a raging populist, though no doubt some Labour activists will not feel comfortable about what he is doing. But they are not the priority.
The voters are. Shearer's job is to jolt them so they start taking heed of Labour's wider message, particularly the fresh direction the party is taking on economic policy. There is also a feeling that there is now a more receptive audience for that message among the middle classes who are struggling to get ahead, along with the hundreds and thousands of owner-operators of small businesses.
To that end, Shearer has scheduled a major speech for a week tomorrow - two days ahead of the Prime Minister's annual statement to Parliament which outlines the broad details of National's policy programme for the next 12 months.
Shearer's address will seek to define the parameters of what is likely to be the most crucial political argument of the year - whether the time is now ripe for Labour's more "hands-on" approach to economic management.
It was almost serendipity that one of the last acts of the summer silly season was to throw up the Business and Economic Research Ltd report questioning KiwiRail's mothballing of the freight-only Napier to Gisborne line.
You would be hard pressed to find something else which so starkly displays the increasing divide between National and Labour.
Not that long ago Labour would have ducked for cover and called for a comprehensive cost-benefit analysis of the line's future potential and risks.
Shearer clearly believes the time for such fudging is past. Labour has to be clear about where it stands. Shearer says Labour would reopen the line. Full stop.
The cost of repairing damaged track would come from money designated to upgrade the state highway between Napier and Gisborne to cope with the increasing volume of logging trucks as the region's harvest of exotic timber escalates.
That would require explicit government intervention rather than leaving matters in the hands of KiwiRail, which is required to conform to far stricter measures of commercial viability.
Such intervention is not without political risk, however. Transporting logs by train has long been flagged as the saviour of the Napier-Gisborne line. But it has become a mirage. The reality is that for the last decade the line has carried minimal tonnages, such that closure would increase the number of trucks on the state highway by just six per working day.
Can Labour afford to be seen to be promising to subsidise something that many say they want, but few are willing to use?
Labour argues that National has treated the global financial crisis as a blip and it will be business as usual for the world economy soon enough. Labour says the reality is that adoption of a more hands-on style of economic management is a necessity because market policies alone are no longer sufficient to deliver reasonable levels of economic growth.
National claims the shift in Labour's thinking towards greater intervention is a throwback to the past. National says Labour is cynically trying to appeal to people who do not like change. Adopting hands-on management inevitably entails more government spending.
If nothing else, however, Shearer's more clear-cut position-taking will offer something voters have not enjoyed for a long time - a real choice between the two major parties on the fundamentals of economic policy. Expect, therefore, the ensuing debate to run and run once the new political year officially gets under way next Wednesday with the first Cabinet meeting of 2013.