It astounds me the number of "professional" photographers out there that still don't understand the use of fill light, be it via strobes, speedlights or reflectors, when working outside. Why use them? Because the sun is fucking fickle, that's why. It's either too bright, causing your subject to squint or causing their eyes to water, or it casts some heavy ass shadows. Just because you're outside and there's this giant ball of nuclear gas up there doesn't mean your scene wouldn't benefit from a fill light.
Of course, I understand that not everyone can afford strobes or speedlights, but reflectors are cheap. You can even make one with some tinfoil/aluminium foil and cardboard, but it will throw off your white balance somewhat. That said, if you're going to charge for your pics, invest in your equipment to do it right, ESPECIALLY for weddings when you only have ONE FUCKING CHANCE to do it right. Your reputation is on the line, as is your wallet.
This is my setup for a typical 11am-4pm outdoors shot in full sun: Canon 580EXII on camera, E-TTL but I set my FEC for somewhere between +1/3 and 1, depending on my distance. I will also occasionally throw a Gary Fong collapsible difuser on the speedlight as well, but it requires adjusting FEC accordingly. I'll also shoot in ISO800 so that I am not pushing my flash as hard and benefit from faster recycle times.
Shadows are awesome, and the sun is a fucking awesome source for them, but too much shadow is troublesome. Can it be fixed in software? A lot of the time it can be, but why spend so much time on editing when something simple can be added to your shooting routine? Unless, of course, your time isn't money.