Will it be the Oscar-nominated actor, the academic, the painter, the soap star or the funnyman?
"One thing Franco hasn't decided is what his personality is as a star," Stephen Galloway, executive editor of The Hollywood Reporter, told ABCNews.com. "He's proven his chops as an actor but not quite as a star. Anne Hathaway has shown she's charming, funny, modern. We kind of know what we're getting with her. We don't know with Franco."
Don't expect another Ricky Gervais, however.
"If you're looking for someone to call people out, we're not your hosts," Hathaway told The Hollywood Reporter, which did an interview with her and co-host Franco for its upcoming issue.
The Academy, desperate to appeal to younger viewers, is already taking a risk with Hathaway, 28, and Franco, 32, the two youngest emcees in awards' history.
Hathaway initially turned down the offer to host the Oscars, until she heard Franco was in.
"He's so brave and so willing to make unconventional choices. All the ways I was worried about it going wrong, it wouldn't go wrong in any of those ways. It could go wrong in entirely new ways," she said with a laugh.
Hathaway got some reassurance from Alec Baldwin, last year's host with Steve Martin. "When I ran into him a couple weeks ago, (he) said, 'The thing to remember is, it's not about you.'"
Franco heard from Jon Stewart, who hosted in 2006 and 2008. "He said we'll be fine because we're more insiders, though I feel like kind of an outsider."
In some ways, Franco, with his multiple interests, is something of a Hollywood outsider.
At this year's Sundance Film Festival, Franco did an art installation dramatizing the first three episodes of "Three's Company," by recreating the characters' living room and dubbing over their lines.
This week he'll make another appearance on "General Hospital" and exhibit his art in Los Angeles before heading to the Oscars.
Galloway wonders if his multi-tasking personality will prove too much for the Academy. "The last thing the Academy wants is someone too avant-garde," he said.
"We do know he's multi-talented -- he's getting his Ph.D. [at Yale], he's written short stories, he acts, he does his own art. He has a host of talents," said Galloway. "But there's no known proof yet that hosting is one of them."
One good thing about hosting, Franco doesn't have to worry about losing for best actor -- he's nominated for "127 Hours."
"Well, nobody is shy about saying Colin Firth is going to win. I've accepted that. By hosting, it makes it easier to go to the events and not feel like a total schmo," he told The Hollywood Reporter.
Franco has been preparing for this new challenge, and if the videos he has posted on the web are any indication, he'll most likely bring his sense of humor on Sunday.
In one video posted on "Funny or Die," Franco has a conversation with producer Judd Apatow, who gave the actor his big break on the short-lived but critically acclaimed NBC series "Freaks and Geeks" in 1999. Franco asks Apatow, who recently hosted the Producers Guild Awards, for tips on hosting the Oscars.
After Apatow offers him X-rated advice, Franco decides to recycle the jokes that worked for Apatow at the Producers Guild.