I've been in Singapore for 3 years, and agree that it is a really easy place to live with young children. I have a son of 5 and am expecting again in May. Here are a few things that I thought would be helpful..
The Expat Singapore website may be an interesting read but it is also known here as the Angry Board - a lot of aggressive, frustrated people on there, and wise to take many opinions with a pinch of salt!
Try and make sure you have good healthcare insurance, else it gets very expensive, particularly if you are thinking of having another baby - most policies have a period of 9 months to a year before they pay out for maternity costs.
You can get inexpensive domestic helpers here, which can compensate in a small way to not having family help. A lot of people have full time live-in helpers, but I would strongly advise you to only do this if you are 100% sure you want to; it doesn't work for everyone. I had one and hated it - I now have someone once a week to clean and iron, which suits us much better.
The weather - this one is hugely pertinent for me being 8 months pg - my God, it's hot here! Of course it's not a deal-breaker in any way, but if you don't like the heat you may find it hard. Some people love it, but others are forced to spend their lives in air conditioned places!
Generally it is a good place to live - it's a very safe and easy place to be with young children, and if you live in a condo it's really easy to meet people. Let us know if you decide to come!