It's a hard call. I'm a carnivore, he's a veggie. We both feel that our eating habbits are the best because (fill in the blank).
For us, we are looking at older-child adoption. So, it is likely that the child will already be one or the other. In which case, we would continue those eating patterns until a child was ready to make the call on their own.
But a baby you bring up from day one? I suppose that depends on what the parents are most comfortable with. Also, on whether the parents are commited to ensuring that a growing baby gets all the nutirents they need.
If you feel very strongly that you want a veggie kid, talk it out with the hubby and a pediatrician and go from there.