I have been goggling for links...maybe these links might help

http://www.tuohey1.freeserve.co.uk/susie/intro.htm

http://www.vet.cornell.edu/Public/FHC/diabetes.html

http://www.felinediabetes.com/

The above site has a message board...

http://www.catdr.com/cat_care_diabetes.htm

The above site is very detailed

Here is a quote from Jen Luckenbach (I hope you don't mind me quoting you Jen) when I asked about diabetic cats care, for someone I knew.....

I treated Y.Lee for diabetes for 6 months before he gave up and stopped eating. He needed regular blood screenings at first to determine the amount of insulin, but not really that much EXTENSIVE care. He required an insulin shot twice a day. And except for the fact that you needed to administer them at 12 hour intervals, there was nothing demanding about this. Most people that work full time can manage feeding/medicating at 12 hour intervals.
He needed a special diet, but again there was nothing overly demanding about this.
The insulin and needle/syringe costs were nominal. The special food is probably only SLIGHTLY more expensive than average food. The blood tests however can mount up. But once the cat is regulated, these costs go down.
I only worked with one diabetic, I suppose it is possible that others need more care, but really, it was not that much of an imposition on us humans to treat Y. Lee.