JPEG offers two advantages (other than how many images you can fit on a card) that may be extremely significant under the right circumstances: the speed of workflow after the shoot (assuming you've gotten things right in camera) and the speed at which you can shoot.

RAW files take a lot longer to write to the card than JPEGs do (and RAW+JPEG takes longer still), so in the genres of photography where you need to take a lot of pictures quickly, a given camera will almost always perform better when shooting JPEGs. That is important to sports and wedding photographers as well as to photojournalists. The absolute last thing you want is to have your shutter release locked or delayed because your camera's buffer is full. And it doesn't matter whether that means getting the 9-10 FPS of a high-end speed demon like the Nikon D3s or the Canon EOS 1D Mk. IV or squeezing 3-4 FPS out of an older or entry-to-mid-level camera, having to wait for the buffer to write out to the card may mean missing the only shot that counts.

And while JPEGs limit you in what you can do in post-processing, they also limit what you have to do in post-processing. That difference in turn-around time can make a big difference to the amount of work you are able to take on, especially when you're working at the lower-priced, more cut-throat end of the industry. It may take (on average) a thirtieth of a second to take a picture, but it takes a lot longer than that to review, cull, and refine them afterwards. Even an extra ten seconds per picture (or series) can mean giving up another shooting day, so the financial advantages to shooting JPEG and getting it right in-camera are very real at that level. Most of the better cameras will let you set custom picture settings (more than one) so that your "signature look" can happen primarily in the camera.

Of course, if you get it wrong in-camera shooting JPEGs, you can't hide your mistakes nearly as easily or as well. So you need to balance the business risks of missing the shot, taking too long in post and having the ultimate control in post. A best-case compromise might be to shoot the formals (the ones that you can take some time over, and that have to be absolutely perfect) in RAW and the spontaneous action in JPEG. But it is a business decision, not a photographic one.