Grier,
We have nothing against southern Europe. Italy has always been #1 on our list and we are simply waiting until the children are a little older to ensure that they will fully appreciate and remember it. Spain/Portugal/Morocco is also on the list, but the threat of intense heat is a drawback. Croatia and points eastward are probably about 5-6 years in the future.
We're trying to balance our interests with what is finacially feasible and also where the children will be welcome, safe, and have interesting things to see and do.
Clearly, the question of where to go next would be answered differently if we were not bringing three school-age children along. But we like doing things as a family.
Also, since we already endure very long, cold winters, we hesitiate to pick places where temps will be cool-cold in the southern hemisphere. I know that the barrier reef in Australia is tropical, so that is a distinct possibility. And I'm sure we could handle the temps in the 50s and 60s for a few days in Sydney. But to be cooler than that or for longer than that would not bode well for our mental health.