An article on the ABC News web-site:
What a great idea!
Not having looked at anything but it would be sensible to link it in with other MtBike trails Eagle park for example. Looking at the lay of the land, plenty of scope for trail access I would suggest:
Nice idea, but linking off-road to Eagle Mountain would be a challenge. There are a number of very deep gullies in the way! Steep road reserves, some with walking trails do exist northwards, Pony Ridge Rd being the first of them. Round the top via Sheoak and Waverley Ridge Rds is quite reasonble though.
What a great idea. Seems like a few of the options mentioned are not mutually exclusive and could actually all work well together.