I lean towards what Coops said TBH on the space requirements thing ... for everything else I do indeed shoot raw, but for motorsports I still tend to shoot JPEG 95% of the time.
I switch to raw usually if I know its gonna be a tricky capture or I am going to have to work it more in PP, or when I am in the pit area, or if I know its going to be a low number of shots / not many chances to get a shot possibly combined with a fairly good chance of very high keeper rate.
My main reason? ... well, I dunno about anyone else but at a full 3 day racing event I can produce a good couple of thousand shots, and at ~20MB per raw file, that is a large chunk of disk space in anyone's money.
Maybe my maths are deceiving me as I am ill today, but in my case we would be talking ~40GB for RAW files versus ~7GB for the same thing in JPG. Then you have to factor in another 40GB for my RAID 0/mirrored hard drive, plus two more chunks of 40GB on the backup drives have (onsite and offsite).
So ... whilst yes disc space is relatively cheap, its not that cheap that I don't stop to think about a net difference between the two in the region of 130GB every time I do a weekends shooting 
The other consideration you have to have is how many the memory cards you own or will need for one days' shooting ...
I also think Coops statement about "all the time in the world to dump" relates to dumping from camera to memory, not at home on the computer.
On most DSLRs the transfer rate from Camera to card is still a bottleneck, so burst shooting with raw even on the fastest cameras and memory cards starts to hit a limit way quicker than it does when shooting jpg.
Guess this though heavily depends your kit, how and what you shoot and how the bust limit, etc affects you ...
I find my use of burst rates does not generally go beyond the capability of what raw could dump to the card before I would want to shoot again ... but I do like the buffer JPEG gives me over raw.
Its all horses for coarses at the end of the day IMHO ... really depends on your needs, kit, budget, skill, requirements, target media and audience, shooting conditions, and of course your desire to sit editing your photos to the nth degree once you get back to base 