Breaking news - Mel Gibson Costly Divorce

"It's a billion-dollar divorce!" says celebrity divorce lawyer Raoul Felder.

Yesterday's headlines that Mel Gibson, 53 and his wife Robyn Moore, also 53, were filing for divorce after 28 years of marriage has now been eclipsed by a handful of thornier follow-up questions. Namely, how much will the split cost the A-lister? How will it affect his reputation? Will it jeopardize the projects he has in development? And perhaps, most tantalizing of all, will it be the costliest celebrity divorce ever?

In short, the answers are: lots, remains to be seen, not likely, and almost certainly yes.

With no indication that the couple had hammered out a prenuptial agreement before their 1980 wedding, Gibson's low-profile wife is now legally entitled to half of everything he's earned over their nearly-three decades together, according to Felder, which could translate into roughly $500 million.

People.com estimates Gibson's fortune to be in the neighborhood of $1 billion (The Passion of the Christ, a labor of love project he directed and produced, pulled in $600 million at the box office, alone), which puts the split on track to be the richest celebrity divorce ever. Other celeb splits with lots of zeroes include Michael Jordan paying $168 million in his 2006 divorce from his wife Juanita, Steven Spielberg's shelling out $100 million in his 1989 split from actress Amy Irving, and Sir Paul McCartney's $48.6 million 2008 settlement with Heather Mills.

Obviously, half of a billion is still a nice chunk of change to have left in your bank account. So don't cry for Gibson yet. The stickier issue, however, may be whether the split will tarnish Gibson's reputation as a devoted father (Gibson and Moore have seven kids ranging in age from 9 to 28) and a devout Christian -- an image already damaged by his 2006 arrest for drunken driving and the bizarre tirade that accompanied it.

"If he was Matthew Broderick or Tom Hanks, the answer would be yes," says Felder. "But the public has been desensitized already to this fellow, so I don't think it's going to affect him at all."

Felder doesn't expect the divorce to have much effect on Gibson's upcoming projects, beyond the fact that his wife will have to be bought out for her share in them. And that could get complicated since he has more than a dozen films in various stages of development, ranging from Mad Max 4 to an adaptation of Ray Bradbury's Fahrenheit 451. "This divorce could be very difficult because he's one of the few stars who acquires properties and gets involved with them on different levels, like directing and producing," says Felder. "These are very hard to value, and that makes it not a simple divorce."

Still, Felder doesn't expect that the couple will turn their split into a drawn-out battle. "If [Moore] is like any other wife, she'll want her money now. She doesn't want to be a partner in a movie that may or may not be made 10 years from now. I think she'd want to be paid up front. Until then, I'd try to keep it quiet. Because one of the problems with these divorces is, if you unleash the dogs of war, you can never put them back in the bottle again, to mix metaphors. But who knows, it may wind up being World War III -- you can't tell."