That is because entries are not open yet so they've still got this year's results pages up. I was thinking of entering last year but didn't get round to it in time for various reasons - as far as I remember you had to e-mail some bloke and ask for the entry, rather than being able to fill in a form. Probably because it's more popular than some of the other Great Run events.
It has fast-paced club places; you have to e-mail and ask for one, linking to the evidence of your qualifying time. Can't remember what it is for men; if you click on the 'elite athletes' page and then scroll down past the actual elite criteria you should find it.
I think: one individual prize and one team prize is enough. As Dean says, vet prizes are there so that people who don't run fast enough any more to be competitive for the open prizes can still compete. If they do run fast enough to win the open prizes, they don't need a prize for still being fast as a vet.
The strangest age group prize I've seen recently was when it was one individual prize per person, but as well as the usual vet categories, the race also awarded prizes for first male and female senior! As most of the fast seniors were likely to place in the overall top three, and many of the fast vets were faster than the fourth senior, the people winning those prizes ended up being well down the field.