I also have been thinking a lot about Adelaide Station, and how it's a dead-end. I'd like to see a Melbourne-style ring, but that could perhaps be part of a CBD subway. In any case, through-stations are much more efficient than dead-ends.
I love that they build Wayville Station each year for the Royal Show. But I wonder they don't build a permanent one and use it on all expo days. (Like Cheltenham Park Race Course used to be only on race days) I fully support the shuttle, though. Brilliant idea.