It's a combination of choice and necessity for me. DH's work comes and goes so the money is a bit irregular. We could probably manage with just him working and we've done for short stretches (doing it again now) but it's hard financially and he gets really stressed.
I've always been really happy working. Though I'm really enjoying my time off now (though I'm actually still going into the office and working 3 days a week, I'm just taking DS2 with me and not worrying too much about how much I'm getting done).
Best solution would be for both DH and I to work part-time.
It's looking like I might not find anything till next year which is a bit longer than I would've liked. We'll see...