It's easy to postulate that there's a clear pattern to the practical ethics of a government: when newly incumbent, it's easy to create distance with the previous administration by instituting a raft of new measures that speak to the ethics of rule. Later, as the government finds itself somewhat hamstrung by its own rules, it relaxes those standards. By the time the government is ready to be turfed out, it can be seen as positively venal, and an easy target for the next administration.
In 1996, although I don't recall any strong lapse in ethics of the Keating government, incomer John Howard promulgated a Ministerial Code of Conduct, only to relax it after seven (!) Ministers (Jull, Sharp, etc) were obliged to resign due to undeclared conflicts of interest and misuse of allowances. Peter McGuaran, for one, made it back to the cabinet.
Kevin Rudd sounds like a very principled man. He is sticking to a number of electoral promises that he'd probably rather not keep (eg tax cuts), and that others would prefer he didn't keep (eg retaining superlatively generous funding for a number of private schools as instigated by Howard).
His appointment of Harry Jenkins as Speaker of the House of Representatives made a stark departure from the previous office-holder, the partisan David Hawker. It could even be said that Rudd didn't know what he was in for: Jenkins has been particularly rigorous in keeping his own government in line (for example, requiring Ministers to answer the actual question that was asked of them!). Against that argument is the fact that Jenkins was Deputy Speaker in the last Keating government.
It remains that Rudd is highly principled. An article in today's Herald gives some insight into the man, which speaks of a significant break from the previous Prime Minister, and not just due to this "early days" syndrome.
And his government is also set to sign the Optional Protocol to the United Nations Convention against Torture, which Howard balked at, probably because the consequent laws may apply to "Australian officials overseas who co-operate with foreign intelligence agencies known to engage in torture".
I still have strong reservations about Rudd's ability to handle the reins of government. Of overriding importance is the setting of carbon emission caps as soon as possible - providing industry with clarity and leadership. And the commitments to tax cuts and those special private schools were wrong to make in the first place, campaign or no*.
Yet... it's early days.
Postscript 3-March: I've heard rumours from high-level public servants (across departments)that Rudd has been very difficult to get to commit to decisions. This would jibe with his apparent propensity to set up committees on a welter of issues. But it doesn't make sense in the context that it's his ministers that should be making the specific departmental decisions. One example given was in relation to the budget - yet I wouldn't be surprised if these ones take time to sort out. Still, something to watch out for.
*In mitigation is some analysis on the decreased commitment over time of the Australian public to a particular side of politics (mentioned last year). I would expect this to lead to an increased "what's in it for me" vote, which would make it hard to opt out of a tax cut auction at election time.