It seems somewhat accurate, though I don't really like the sensational tone or the highly unlikely anecdote.
A neurologist says that if he can get to a stroke victim within 3 hours he can totally reverse the effects of a stroke...totally. He said the trick was getting a stroke recognized, diagnosed, and then getting the patient medically cared for within 3 hours, which is tough.
The quoted part has a kernel of truth with a load of BS wrapped around it. If someone is having an ischemic attack (i.e. lack of blood to the tissue) due to a blood clot, there are "clot buster" drugs that they can only administer within three hours of the onset. The drugs can reduce further ischemia. They are good stuff, but not some magical cure.
S * Ask the individual to SMILE.
T * Ask the person to TALK to SPEAK A SIMPLE SENTENCE
(Coherently) (i.e. . . It is sunny out today)
R * Ask him or her to RAISE BOTH ARMS.
These loosely coincide with a few signs of a stroke as I was taught them: Drooping facial features on one side, slurred speech and pronator drift (raising one arm while the other hangs low). I've never heard of the tongue thing.
It wouldn't necessarily hurt to do the tests listed in the email, but it isn't a trustworthy way to diagnose either. If you have any reason to think someone has had a stroke your first step should be to call 911.
Also, like CAnnoneer said, the chief complaint of many stroke patients is a severe headache.
If you want the full "official" list of signs and symptoms, let me know and I'll post it.
Disclaimer: I am only an EMT. Nothing I say should ever be construed as medical advice. Any advice I have on caliber selection, however, can be trusted.