All I can say is try before you buy. We went over for a month earlier this year and are going back again Jan and Feb 2008. We sat down many a time with my wife in tears as we talked about this big move.
I will be giving up a very good job and my wife hopes to semi retire. (You must consider this in your decison)
We have decided to go for it and if either one of us says it is not for them then we both come back together regardless of how the other feels about staying. We will however stay at least till we get citizenship as we have heard of people coming back to England regretting it and then going back to Aus again. (A very expensive way of doing it!)
Our children have all grown up and have set up homes of their own now, so we will always be returning for visits which will make it easier.
We think it is a great place but you both need to be sure about this.
If you have family or friends over there it wil help.
Regular phone calls and a web cam are also a good idea.
Hope this has been useful.