I've read online that some people are questioning why not have longer series, but just count the first 2-3 tests for WTC points. Interestingly, this would give the following if the Ashes followed that process.
2 Tests (points 60/0/20): Aus 1-0-1 Eng: points
Aus 80 Eng 20
3 Tests (points 40/0/13): Aus 1-1-1 Eng: points
Aus 53 Eng 53
4 Tests (points 30/0/10): Aus 2-1-1 Eng: points
Aus 70 Eng 40
5 Tests (points 24/0/8): Aus 2-2-1 Eng: points
Aus 56 Eng 56
So I guess this proves that all Ashes series in future should be only 2 Tests in order to identify the real World Test Champions