1. Labour has the more experienced campaigning machine.
But day one of the pre-campaign saw an important psychological boost for Labour as the first error was made by the Conservatives - and by David Cameron himself - as the Tories downgraded and the reasserted their pledge to recognise marriage in the tax system, while refusing to say what they would do.
This will remind both sides that many more on the Labour side have been involved in the heat of the campaign before.
2. The Conservatives do not seem ready to pre-publish their manifesto.
The marriage commitment was just one example of a broader problem on policy for the Conservatives. They have not worked out what the status of several policy commitments are.
Sam Coates of the Times' Red Box blog spots a number of 'confusing' omissions from the health manifesto, and reports this official response.
A spokesman tonight said that "almost all" promises made over the last four years in health still held - many just hadn't been mentioned in the draft manifesto. He couldn't explain a reason for the omission, though
3. The Conservatives will fight the most personality-based campaign we have yet seen in British politics.
David Cameron is the Tories' number one electoral asset; and the extent of their reliance on the leader perhaps their main potential vulnerability. Daniel Finkelstein suggests he is just about their only electoral asset, stating candidly on Newsnight that they would have hoped, by this stage, that Cameron would not be their only symbol of 'change' that the Tories have, 'but they are not in that position'.
This helps to explain why the TV debates make sense for the favourites as well as the underdogs, by making a personalised battle the centrepiece of the campaign. But could they also be used to exploit a key concern about the Opposition - that Cameron's party has changed much less than he claims, something that the Conservative campaign strategy itself now tacitly acknowledges?
There is a tendency to see the increasing personalisation of politics as an inexorable post-1960 trend of the TV age. Up to a point. But neither campaign was especially leadership focused in 2005. Perhaps paradoxically, the winning campaigns which focused least heavily on the premiership candidate were Blair's in 2005 and Thatcher's in 1997.
4. The parties are digging in for a close contest
Sam Coates again notes the focus of Tory shadow cabinet campaigning was (rationally) in seats which would leave them short of an overall majority. (And the impact of 'target seat' strategies can be somewhat overstated, as analysis of Labour's landslide showed in 1997).
The Liberal Democrats may not have been prominent yesterday, but they are likely to get more attention than ever before, as Steve Richards notes today.
5. We'll hear more of the 'inside baseball' of the campaign than ever before
One of the impressive things about the 'no drama Obama' presidential campaign was how few of the internal campaign debates found their way into the press, in stark contrast to both the Clinton and McCain campaigns, and how little staffers sought the limelight in media briefings.
The British campaigns look unlikely to emulate that. The increased online coverage of politics by the mainstream media gives the political lobby much more space to muse on the relative influence of Steve Hilton, Andy Coulson and others in the Tory campaign. (Though, on the Labour side, media discussion has mostly been on the relative influence of Cabinet ministers - particularly Peter Mandelson and Ed Balls - on political strategy, which may partly reflect how many of the Cabinet - also Douglas Alexander and both Milibands - cut their teeth as strategists and advisors before entering Parliament).
Osborne aide Rupert Harrison is even taking credit for coining the phrase 'dodgy dossier', as Paul Waugh reports, to describe Labour's comprehensive list of Tory spending commitments and aspirations. That seems bizarre: the term is in such constant use that it might be a candidate for a place on John Rentoul's banned list: for example, Next Left last used it on Saturday, to describe Phillip Hammond's dodgy IHT statistics.