Dominic Crossley-Holland on Broadcasting

It's a truth universally acknowledged that a TV network in possession of a waning fortune must be in want of a hit. Last night, Billie Piper tried to deliver just that as Fanny Price in ITV's Mansfield Park. Northanger Abbey and Persuasion are to follow, joining a truly Austenian spring, with Anne "Devil Wears Prada" Hathaway already trying to seduce us with Becoming Jane in the cinemas.

If spring is a time of change and growth, there's been plenty of the former - if not the latter - at the main commercial networks this year. In fact, the line-ups at the top of all three have altered, proving that controllers can no longer enjoy prolonged hibernations in the Groucho or Soho House, if they ever could.

At ITV, the new executive chairman Michael Grade is firmly ensconced; at Channel 4, Kevin Lygo is moving upstairs as director of television and content; and over at Five, Lisa Opie is getting stuck in as the new managing director of content. Beyond some uncannily similar job titles, it is interesting to note the common words and themes that seem to be emerging from this new ruling troika.

Let's start with ITV. After the quiz TV scandal engulfing all channels, the Austen season at least gives the network a feeling of much needed quality and dependability, although whether that adds up to Grade's stated ambition to raise the network's "creative ambition" is another matter. What Grade actually said as he unveiled ITV's drop in profits a fortnight ago was this: "There is a lack of innovation in our programming, partly resulting from a fear of ratings failure... my immediate priorities are developing the strength of our programming... we must be more innovative and take more risks... we must be more relevant and we must be ahead of audience tastes... in particular, we must regain our pre-eminence in drama series on ITV1 at 9pm."

Cynics might say it all sounds a bit like his predecessor Charles Allen, and that Grade's fine words merely fly up while his real thoughts remain below. But his words do reflect a re-energised ITV and bear at least passing similarities to the spring offensives from Channel 4 and Five, which also stress innovation and risk-taking, and the championing of commissioned programmes.

And it's home-grown, quality productions and familiar faces that have delivered some of the biggest hits of the past few months. Channel 4's Grand Designs opened its new season with a whopping 5.5 million viewers, one in four of everybody watching TV at the time. ITV's Morse spin-off Lewis, starring Kevin Whately, has been drawing audiences of between seven and eight million; BBC2's Top Gear ended its series with almost eight million viewers; and on Sky One, Terry Pratchett's Hogfather drew one of the highest ratings ever in December and was the most popular UK-commissioned programme the channel has shown.

So, with the prices of American imports and acquisitions going Sky high since Murdoch snatched Lost from Channel 4 for a rumoured £20m a series, are we seeing the beginning of a new emphasis on home-grown programming? Kevin Lygo has already said that as part of his new, more strategic, role he'll look at whether the current spend on American acquired programming is sustainable. Would that money, Lygo asks, be better spent on original commissioned programming instead? Similarly, he'll examine whether the current spend on daytime is the right way to proceed given the intense competition with BBC1 and ITV.

Five is battling with a loss in share of about 15 per cent of the upmarket ABC1s so beloved of advertisers, so it seems a new emphasis is just what the doctor ordered here, too. Lisa Opie says: "We are looking for things that are innovative and not derivative. We are asking indies to come to us with fresh ideas, and are saying that we are prepared to be bolder and take more risks... We want our specialist output to be distinctive and not afraid to tackle serious issues, so no tacky sex please."

Among the programmes Five is trumpeting is Donal MacIntyre's new series The Curious Tribe, in which a tribe of hunter-gatherers is brought from the jungle to experience Britain, and Make Me Brilliant, which will scour classrooms in search of Britain's "forgotten geniuses".

None of which is to say that acquired programming is on the way out - in fact, anything but. ITV has built up its acquisition team and made a point of buying from all the studios last year. Five is hugely dependent on CSI and now has its new digital channel Five US, while Channel 4 has found success with its latest import Ugly Betty. But maybe, just maybe, we're seeing a spring for home-grown and more aspirational programming too.

An interesting nugget came from Five's chief executive Jane Lighting at last week's Commons media committee hearing. While most of the heat and light was generated by the quiz TV debate, the original purpose of the hearing was the future of public service broadcasting. Lighting seemed far from wanting to wriggle out of the channel's commitments. In her view, "the moment you drop important areas like the news, or children's, you fail to have that breadth of coverage. You become one of many." Contrast that to Michael Grade, who admitted that children's programming was unsustainable and would disappear from ITV1 "in the medium to long term", and that regional content on ITV would probably end up as just news.

There will be further clues about where we are headed this Thursday, when broadcasters' annual statements of programme policy are published. As usual, they are likely to amount to a litany of fine words stressing quality, public service and UK production. That will please the regulator, but might they signal a bigger shift?

My money is on it being business as usual for the networks, with bottom line being the determining factor. As Jane Austen's mother tells her daughter in Becoming Jane: "Affection is desirable, money is absolutely indispensable."

Coming soon to a screen near you: goodbye Tony, hello Gordon

He's here, he's there, he's everywhere. Rather than the usual valedictory programme or two, the manner of Tony Blair's parting means we're being inundated with them, even while he's still in office.

First, we had the docu-dramas spawned by the antics of cabinet colleagues, like A Very Social Secretary and Confessions of a Diary Secretary, and then The Trial of Tony Blair. But now we're into Blair season proper. Not only was Cherie doing the Lent Talks on Radio 4 last week, but it was also the conclusion of Michael Cockerell's quite brilliant series Blair: The Inside Story on BBC2. Channel 4 has commissioned Andrew Rawnsley to look at the Prime Minister's legacy, and all the main channels promise more in the pipeline.

But just when you think it's safe to turn on the telly again, prepare for a new wave of programmes on... Gordon Brown. First out is Five's Gordon Brown Meets the Ten Year Olds, which promises to do what it says on the tin. As the programme's PR blurb says, it's likely to be more insightful than most encounters with the Chancellor.