JPG? Hell no.
Well, let me re-state that answer: The only time I will shoot in JPG format is when (lack of) time makes it impractical to shoot RAW. A good example of this in my business is at a motorsports event, where I might shoot 3500 images in a day; these all need to be downloaded, culled, and sorted, and it's all we can do to get that done and still be able to fill our onsite orders. There is simply no time to wait for RAW conversion.
On Tuesday afternoon I shot a handful of frames of my dog playing with a ball in the front yard in the late afternoon (October) sun. I was using my Nikon D3, 400/2.8 VR, ISO 500, Large/Fine JPG, WB set to "sunlight". Once I downloaded and viewed them on the computer, I was completely dismayed at the horrid color; everything was way too yellow and contrasty. Had I shot them in RAW, it would have been simple to produce a great final image, but I was stuck with a 'less than good' result, just because I thought I'd play around with some JPG files.
More anecdotal evidence that JPG sucks:
I shot a wedding recently. I always use my D3 as the primary body, and keep a D300 in my bag as a backup. But on a whim during the ceremony on this particular day, I decided to pull the D300 out of the bag and use it with my 70-200/2.8 VR for some tighter telephoto shots. I did not take the time to ensure the camera was set to RAW before taking a couple dozen photos. The results? Ew...! The JPG shots are easy to identify when I look at the proofs.
Now, I know what (someone) is going to say: That if everything had been set "properly" in the camera - white balance, exposure, 'picture style' (or whatever)... - that the JPG would look just as good, or even better, than the JPG produced from a RAW file. Well, save your effort. I contend that you simply cannot nail every shot, every time. If you insist on shooting JPG's alone, there are shots you will miss...especially when you're under pressure - at a wedding, for example.
I distinctly remember making an argument FOR shooting JPG's - possibly on the old Rob Galbraith forum. This was at least a few years ago, before Lightroom, and before I was shooting 18-20 weddings a year. Now, I can't imagine going back. RAW is a given for me.
PS. Once again, I wrote a response to a Matt Ballard (content-less) "post" based solely on the thread title, as I refuse to click over to his site, on principle. Bear in mind that I have no idea what conclusion the OP came to; I'm only relaying MY thoughts on the JPG vs. RAW question. That said, I am at least grateful that there was a new thread to read and reply to here on PPH.