My understanding of the system, from Euans report on the news is that it would be only during the fire danger season and for large, campain type incidents. The day to day responding would not change, and when a big one hits, the normal vollies would be initial attack, then as relievers, the city folk would come in for a shift or two. Their training would only be bush fire training ie. BFF1, and i imagine they would need to be working with full members when on the fire ground for supervision/safety purposes.