Step right up to the roulette table, media moguls. All of you must place bets, and not to heighten the pressure, some of you are going to be proven woefully, publicly, inescapably wrong.

For years, studios have been able to dabble in the new-media world with a sense of security since their core businesses would continue to drive near-term earnings. Yes, big changes were coming, but they seemed far enough away that the existential threats they posed remained largely theoretical.

Increasingly, though, fundamental questions about strategy are becoming more pressing, requiring media movers to take a stand — and gamble on being publicly exposed, relatively soon, for potential miscalculations.

As it happens, two big wagers on the value of content vs. distribution — placed on opposite ends of the spectrum — are being made by cable CEOs who both ascended to their corporate perches partly by virtue of familial inheritance: buttoned-down Brian Roberts, who is staking Comcast’s future on wedding content with distribution by acquiring NBC Universal, and the mercurial James Dolan, who has floated plans to spin off Cablevision’s programming assets — including channels AMC, IFC and WE — from its cable systems to unlock their value.

At first blush, the smart money would look to be on Roberts, if only because of the Dolans’ tumultuous history, having among other things turned the New York Knicks into perhaps the NBA’s most dysfunctional franchise. Yet given all the moving parts in such deals, such an outcome is hardly assured.

Big mergers and Hollywood dealmaking have turned out badly before, of course, from AOL marrying Time Warner to Disney’s sizable overpayment to Fox and Haim Saban for the network currently known as ABC Family.

The difference now, at least in terms of big media bets, is that there’s no waffling about it any longer. With new content-distribution methods evolving at a breakneck pace, misjudging the marketplace could have dire and ostentatious consequences; in the past, projections about new technology had a pie-in-the-sky feel as we theorized about the attributes of a “video jukebox.”

One way or another, today’s major players are being forced to choose paths that simultaneously risk closing off other avenues — or at least allowing their competition to gain a significant jump on them if that’s the way the waves break. Everybody’s contemplating a different solution, but is that through Hulu? Streaming with Netflix? Google’s web-based approach? Apple’s dazzling gadgetry?

Whoever wins, there’s no longer a way to avoid taking sides.

Peripheral factors are also playing a part. The sluggish economy and a recent decline in subscription TV have fueled talk about cord-cutting (that is, people dropping cable or dishes), which could hasten pressure on distribution-based companies to fashion a response. Time Warner Cable got out in front by offering a lower-cost package of channels as an alternative, appropriately dubbed TV Essentials.

Then again, if people really decide to acquire TV content on the cheap — and the evidence remains inconclusive on whether they’re doing that in significant numbers — such moves would at best be stopgap measures. Hence Comcast’s apparent urgency about hedging its bets through a major acquisition.

Finally, there’s Rupert Murdoch, who really occupies a plane all his own in terms of operating with a riverboat gambler’s spirit. Under Murdoch, News Corp.’s gambits have included the acquisitions of MySpace and the Wall Street Journal, the merits of which remain subject to debate, though most have underestimated the intangibles in owning the Journal given News Corp.’s demonstrated willingness to leverage such assets against rivals.

The mogul’s latest much-discussed enterprise, meanwhile, involves the Daily, a made-for-iPad newspaper that (hopefully, for ink-stained wretches) could help validate his unabated fascination with print, a medium many of his brethren have already left for dead.

Whether such applications qualify as essential, to borrow Time Warner’s terminology, there are clearly no sure things anymore — and precious little low-hanging fruit. And while detailed analysis will doubtless go into laying down those bets that eventually pay off, even media moguls are left staring down the barrel of potential irrelevance as they ponder the words of that inimitable philosopher, Dirty Harry: “You’ve got to ask yourself a question: Do I feel lucky?”