This is getting awfully close to the RAW V's JPEG debate. The choice to shot RAW or in camera JPEG really comes down to the situation. For professionals there are times when shooting JPEG makes sense. Event stuff, sports and even general journalism need the image off the camera and ready for the customer almost instantly, so you are not going to have time to do any PP work. There are other professional situations that apply where you control all the variables, say shooting products where you can set the PP in advance.
For everything else, which includes anything that would be shot by a serious amateur (please note that if you are shooting in a professional type situation for someone else then by my definition you are a professional even if you are not getting paid) then I can see no reason to shoot anything but RAW. It is really easy to get the embedded JPEG from the file, or you can always use DPP to do a default conversion, as it will simply apply all of the in camera settings to the image for you. I have almost always shot in RAW since I have had my 300D, although for a couple of years only had 1gb of storage so used JPEG when I needed to take a lot of images at one event. Since LR4 came out with Process 2012 I have been going back and reprocessing a lot of my older images and the difference is almost like having a camera upgrade. I now also ETTR, which I find very beneficial as I still shoot with the 300D as well as now with a 20D. In the case of ETTR I know that I am exposing the image in a way that will require a lot of work in PP to extract all of the information, and that the image on the review screen etc will not look good. The thing that I know is that the finished image will actually end up looking better. I now have a system for general shots that doesn't push the ETTR too far that I will generally have to worry about highlights, is consistent across all shots and can be processed by simply using LR presets. For the difficult stuff then yes I will work the exposure to push everything to where I really want it, but then will need to process every image individually. As others have said the modern "Darkroom" is a much nicer place to be, although I do miss it at times, mostly for B&W work, colour is much simpler in the digital domain though. I can do in hours now what was possible if I had had weeks in the darkroom.