I think over time each country will have their own T20 series (IPL, SLPL, PPL, NCL T20, Big Bash, EPL, WI T20, HRV Cup, Standard Bank Pro 20 Series, Stanbic Bank 20 Series, American Premier League) as the primary resource earner.
Round the year we will have the T20 league and the franchise will have bunch of players from different countries as replacement when their home countries will be playing
As part of the tours they will go back to the old times with just test series (Life goes in a full circle) with all modification in tests (Pink Balls, Day night tests) to make them more interesting and will surely be revenue earner. I believe countries like Aus, Eng, NZ and many true followers in Ind, Pak, SL, WI & SA surely will never want to get away with tests. These test would also be a part of the greater World Test Championship
The ODI and T20I will be limited to World Cup, World T20, Asia Cup etc.
New countries will enter cricket world through T20 and if they mature as cricket nations they would also want to take Test playing