Hollywood media companies just made one of their biggest collective bets ever, investing in former studio head Jeffrey Katzenberg's billion-dollar baby, provisionally titled NewTV and intended to remake entertainment with bite-sized videos optimized for mobile.Katzenberg, a former Disney Studios chairman who took DreamWorks Animation public before selling it to Comcast, leveraged his prodigious relationships and track record to raise that billion dollars through his WndrCo holding company.Virtually every Hollywood studio of any size bought in, including Disney, WarnerMedia, Paramount, Sony Pictures, MGM, Lionsgate, 21st Century Fox, Entertainment One, ITV, NBCUniversal and Liberty Global. Other investors include the Chinese online giant Alibaba, Goldman Sachs and JPMorgan Chase. The single biggest investor was Madrone Capital Partners, which is tied to the Walton family (the source of the family fortune, Walmart, is not an investor, though it is planning to launch its own family-friendly streaming service).But as for what the Hollywood studios and other investors will get for their money, well, that remains largely a mystery.Katzenberg and recently named chief executive Meg Whitman (a former CEO of HP Enterprise) have only clarified a few of the project's mysteries. They plan to make and distribute short-form video made with far higher production values than most of the short-form material seen on social-media platforms such as YouTube.NewTV won't compete directly with online streaming giants Netflix, Amazon Prime and Hulu, Katzenberg said. The high-quality content on those sites has largely been focused on programming at lengths and aspect ratios more typically seen on traditional TV and movie theaters.Still, dodging the online behemoths seems prudent, at least from a pure firepower standpoint: Netflix alone plans to spend $8 billion this year on original programming (some critics suggest the company is actually spending $12 billion, when long-term commitments are added). The rejiggered Amazon Studios says it will spend $4.5 billion this year. Even Apple, another company with lots of ambition and even more unanswered questions, already has committed well over $1 billion to a hefty slate of programming.But there's no doubt that a niche for short-form, high-quality, mobile-focused content almost certainly exists. Shorts of many kinds are more popular than ever.Sensing that opportunity, the U.S. streaming giants have begun investing in short-form content, such as Netflix's Comedians in Cars Getting Coffee, an Emmy-nominated series from Jerry Seinfeld. So have subsidiaries of the Big Three Chinese online companies, not just Alibaba, but also Tencent and Baidu.Pay-tv channel ShortsTV has built a following across U.S., European and Indian providers with its library of 5,000 short films from around the world. The channel also distributes in theaters the annual collection of Oscar-nominated shorts in the live-action, animated and documentary categories. This year's Oscar shorts release set a series record, grossing $3.5 million.Many of those short films indeed might the kinds of projects Katzenberg and Whitman intend to make. The best of them feature big-name talent, high production values and stories that far outstrip what's typically seen from all but the most ambitious and well-funded YouTube influencers. Creators often talk about the freedom possible with the short format, which can ignore the straitjacket of traditional TV's 22-/44-minute lengths to tell the best tale.Creating for mobile will be another transition. The idea of shooting for a vertically oriented frame has only been popular since the rise of Snapchat, which was always focused on mobile first. Now, Instagram and other sites have copied the video format, and advertisers have followed suit, chasing mobile natives with messaging made for a vertical orientation.Also in question is whether a streaming venture would provide programming on demand, as Netflix, Facebook Watch and YouTube Premium do, or stream it in linear fashion. ShortsTV, per its roots in traditional film and cable television, programs a linear streaming-video app for its customers in some territories.Pluto.TV, whose site carries 100 ad-supported streaming channels, is one of several outlets creating online experiences that feel a lot like traditional TV. Katzenberg's public comments suggest he's not interested in recapitulating the past.But creating for mobile brings its own challenges. Just last month, Verizon gave up on its pricey three-year experiment in mobile-first content, Go90. Despite deals with some talented creators, the phone company never broke through the background noise to attract audiences or advertisers.It's particularly pertinent to note that Katzenberg's best deal as head of DreamWorks Animation – the $33 million purchase and partial sell-off of online site AwesomenessTV – was also a victim of the Go90 shutdown. Verizon had bought 24.5 percent (at a valuation of $660 million) of Awesomeness, and also signed a $50 million content deal with it for Go90.When that rich content deal ended, the Awesomeness owners decided to get out. They sold the site and production operations for less than $300 million last month to Viacom (separately an investor or owner not just in NewTV but also in kid-friendly video site Pocket.watch, influencer agency WHOSAY and influencer conference operator VidCon).Over his long career, Katzenberg has helped lead several bold efforts to remake entertainment.He was one of the Gang of Four executives who helped transform a somnolent family film and resort company into the media giant that is Disney. With Steven Spielberg and David Geffen, he co-founded DreamWorks, originally with operations in film, TV, music, games and animation. Then he spun out and took public the DreamWorks animation unit, and was prescient enough to make that bargain deal for a year-old AwesomenessTV (compare its $33 million price tag against the final cost of Disney's acquisition of Maker, at more than $700 million).But in trying to reshape Hollywood again, Katzenberg and Whitman will have to see if they can exploit a promising and potentially huge niche before all the established competition already out there grabs all the attention, audiences and advertising. It won't be easy, even with a billion dollars and all that ambition.