What about a radio version of aggregation in regional areas. Sole operators like Ace should then be forced by ACMA to affiliate with multiple metro networks to provide 3-4 different formats. Regional roll out of digital radio would facilitate this.
For example Ace could provide.
Ace Talk (3AW, AFL Nation and the odd local programming. Pretty much their current AM network)
Ace Mixx (Nova/Hit/KIIS style station with mix of programs from both, Pretty much their current FM network)
Ace Gold (Smooth/Gold FM style station with mix of programs from both)
Ace Rock (Triple M style station with the odd Triple M program like Homegrown, My Generation, Rush hour)
Obviously they would be unable to take some SCA programs from Triple M and Hit networks in areas where there is overlap with SCA regional stations but could work in more remote markets or they could just take more ARN/Nova formats and programs.