Go now. You've got this far in the process; you're nearly there. If you delay then you risk losing your kid's enthusiasm and that's a very hard one to do it without!

Turn the job down. I can understand why you went for it- makes you feel you're doing something proactive for your future, but you are nearly there.

Once again thanks to everyone for their replies.
Regarding the 457, I do have it in writing that they will assist with PR after my first year if we want to which to be honest is probably best for us because we have never been to Australia before so are we going with a lets see how it goes attitude. Because of this we are not selling the house but renting it out so will be renting there too.
We will make the best of it and not come back with our tail between our legs just because we have not sold up and have things to come back to.
Anyway I am thinking about taking the job here and delaying the start date to April for Australia because have been looking at flights and they have shot up for mid January and we still have our car to sell and house to rent, which just before xmas isn't easy!
Still not really made a final decision though so keep the good advice coming.
Laura x

A couple of things you should be aware of from the posts above. I am going out on a 457 with my wife. We asked my company for a recomendation on health insurance and they responded that by law the sponcering organisation with 457 is obliged to pay medical cover. You should also be aware there is a great tax break for 457 called working away from home allowance, which basically gives a tax rebate for housing and food, as you are classed as working away from your normal residence. This finishes on gaining residence. Finaly, i was also concerned about the ability of changing employers, and basically it isnt that difficult as long as your new employer agrees to act as sponcer. (I spoke to the Aus Imm in London).
I know its a big step for you, as it is for us, but at the end of the day if you dont like it, then you get a plane back. By the way, have a shop around for flights as there are a few good deals still out there.

When I really can’t make my mind up or get nervous about making a big decision I always think about a quote from Albert Einstein.

"A person who never made a mistake never tried anything new."

How many people have you spoken to about your immigration plans and there reply is "Oh that is something we have always wanted to do".

Like I said to my wife, we can always come back if we don't like it.