There is so, so much to think about when moving to any other country. I've done NYC and currently am in Toronto, both on work assignments with DH.
All the practical stuff is achievable with some good planning, research and organisation.
But I have to be honest, now I have a DD, the fact I don't have any family closer than a 7.5 hour flight (and £500) away and don't have a support structure, i.e you've got to start your friendships from scratch again, is really hard now. Yes you will make friends, but not the one's that you've had since school/Uni whatever.
I think it really hit me hard this week when DH was abroad with work and both DD and I had chronic sickness bug, I had to call an emergency Nanny service (at 20 bucks an hour) to look after DD (and me as it turns out!) as I had no-one else. That was a harsh reality and actually quite scary to think I had no-one I could call on.
Sorry if this sounds like I'm on a downer about being abroad but it's very easy to get swept along with it all and not think about the day to day, being with your DC, in a foreign country, basically feeling like an alien (just because we speak the same language does not mean we're culturally the same!), battling through everything like getting a credit history, you can't get a credit card, blah, blah, blah. It can really grind you down!