Test cricket between Australia and India is safe, but recent tours of Australia by countries such as Sri Lanka, New Zealand and Bangladesh have all become 2 match series due to lack of the drawcard factor, while series against the West Indies and Pakistan are also under the pump; in their heyday, the Windies would command a 5 or even 6 match series. Pakistan of course have their own internal problems meaning that they may have to innovate to play Test cricket. Sri Lanka, New Zealand and Bangladesh have all experienced recent difficulties involving ICL and they will certainly be keen on a solution that brings their players more money without them having to take up any conflicting commitments.
So really, we're looking to England, Australia, South Africa and India to carry the game. So far, our big ideas are all T20 tournaments, which have subsequently put pressure on a couple of Test series, to allow players to participate. Day/Night Tests have long been Australian cricket's holy grail. D/N first class cricket was trialled a long time ago, but the verdict was poor batting conditions after dark. The ball remains the key. Produce a ball that is visible at night and lasts 80 overs and the concept stands a chance.