The title makes it sound like a bad 1980s BBC sitcom, but the this action comedy blockbuster, due out in summer 2010, is probably Cruise and Diaz's best chance to regain box-office cred

Take a look at any "most anticipated movies of 2010" list online and you'll see a familiar collection of sequels and remakes and adaptations. But there's one big summer movie that the list-makers seem to have ignored so far – the Tom Cruise/Cameron Diaz action comedy Knight & Day.

This wouldn't have happened a few years ago. Earlier in the decade, the hype surrounding a high-kicking blockbuster starring Minority Report's Tom Cruise and Cameron Diaz from Charlie's Angels would have been building since the moment it started filming. As it is, the past three days have seen a poster and a teaser trailer launched to almost no fanfare whatsoever.

You don't need to be a genius to see why Tom Cruise's stock has fallen in recent years – Scientology, couch-jumping and films about one-eyed Nazis trying to blow up Hitler with bits of luggage have all helped to transform him from the biggest star in the world to a whooping, air-punching joke.

But Cameron Diaz hasn't fared so well either. There's been an unsettling over-reliance on Shrek and its interminable spin-offs (including next year's Shrek Forever After, Shrek makes up about a third of her IMDb projects since 2001) peppered with gloopily sentimental Oscar-bait such as My Sister's Keeper, generic comedies that she should have grown out of long ago (see What Happens in Vegas) and gormless thrillers like The Box. She needs a hit just as badly as Cruise does.

So both Tom Cruise and Cameron Diaz have a lot at stake here. And although the signs aren't all positive – Knight & Day sounds like the title of a bad 1980s BBC sitcom, the teaser poster makes it look like Diaz has a penis, and the first-choice stars were apparently Chris Rock and Eva Mendez – it probably constitutes the nearest thing to a safe bet for them.

It's a no-brainer for Tom Cruise. His extended cameo in Tropic Thunder proved that people don't find him quite as unbearable when he's being lighthearted – presumably because he's easier to warm to when his boggle-eyed raving is intentional and not part of a leaked Scientology video about world domination. Plus, the trailer suggests that he gets to save the world at the end, which quite clearly caters to his Napoleon complex. And it could potentially play to Cameron Diaz's strengths as well – it allows her the freedom to be at her funny and unselfconscious best, without the downside of having to star opposite Ashton Kutcher.

However, let's not underestimate Tom Cruise's capacity to balls things up yet. Right now Knight & Day looks like an inessential but fun crowd-pleaser that, if nothing else, could help to resolidify the box-office credentials of its leads. But that's only so long as Tom Cruise decides not to attend the premiere in a burning tank, or spend five hours shouting, "No, YOU'RE the man!" at every single person who enters his eyeline, or fake-laugh his way through a billion eerie television interviews prior to its release. It's all his to lose, basically.