With regards to finances or very large purchases, I usually let him handle that. That's his forte.
With a career or job change (which we've never had to deal with), we would both weigh the pros/cons and talk it out. But for the most part, since he's the one working, I'd let him have the final decision.
Regarding the kids, I usually get the final say.
If it came down to moving, that's where the issue would lie. I've lived in this area my whole life...my whole family is here. He's lived here his whole life, for the most part, too. But some of his family has moved away. I'd be willing to have DH take a lower paying job to stay around here...even if that meant moving to a small house or apartment. I'm not sure that he'd agree. Hopefully that decision will never come to us.
As for babies, he pretty much leaves that up to me....he figures that I have to carry them for 9 months and then be with them majority of the time. So he pretty much lets me make that decision.