Bill,
The Greek Islands idea is a good one but unlikely to come to fruition. Too many vested interests and, is it in a time zone suitable for our American friends?
I don't think the Australian Inst. of Sport covers all sports Bill. I haven't heard of any spots there for horse polo players or rodeo riders or sky divers.
The Australian Cricket Academy is in Adelaide and, I'm a bit cloudy here, whilst it may get Federal grants I think most of its funding, non-government, comes from the Australian Cricket Board. I see their past supremo, Rod Marsh, is going to the UK to be involved in a similar scheme.
And yes, our sportspeople are consistent high achievers but when I stand that up against the prevalence of Trachoma in Aboriginal children it kinda loses its polish.
As for, Anything that brings the youth of the world together for good relations, better understanding and common interest - I think Backpacking has taken over this role. At any given time there are thousands of them here, and you don't have to wait 4 years to experience it.

JG / FME