One of the important things to keep in mind when considering WSUD, and how it will evolve over time, is the interplay with other, established, fields such as flooding.
When you step back from WSUD for a moment, and consider its potential, it's pretty obvious that the potential is large. In my opinion, it is also possible to achieve that potential and keep the whole WSUD system quite simple. That's a good thing.
However, the WSUD future is quite a long way off, and we're unlikely to get there in one giant leap. So instead, we take baby steps in the right direction. I think that's a logical approach, but there is a risk to look out for...