What an interesting thread this is.

Firstoff, I'm a vegiterrian. I won't be going vegan until my bones have grown more and they do not need the calcium AS MUCH (I didn't say anymore), but I will go vegan.
But I'd never feed Lady or Sally a vegiterian diet. Like most have said, they are carnivores and I won't take them away from that privelage. I have been feeding them meat for eight years, and I am sure they would be unhappy if I suddenly made their choice whether or not to become a vegan for them. I made the choice myself, and I feel that it would be a bit mean to make the choice that I could make on my own for them.
It sounds like you are very confident in your views and are very well-educated about all of this, Vegan. It also sounds like you are going to take lots of responsibility to switch your pets to a vegan diet, and are willing to switch them back to meat if something goes wrong. Good luck.