www.avma.org (American Veterinary Medical Association) has lots of info on vaccination. In particular, they recommend that each pet parent work with their vet on appropriate vaccinations and frequency.

Locally (upstate New York), three-year rabies and FVCRP ("distemper") shots are becoming more common. Some vets will stagger the shots so the cat gets no more than one shot a year. There is some evidence that the feline leukemia shot may be higher risk than the other ones.

For an opposing opinion, there are groups that are quite aggressive against excessive vaccinations; I can't think of the name off hand but they show up at cat shows.

Vaccines are drugs, and unfortunately like all drugs, sometimes cause problems. I'm sorry that something that is intended to save lives (and indeed is highly successful at this) occasionally causes very bad cancer.