NASWA is good at facilitating knowledge-sharing, but they are no better equipped to build a software product than any state IT department. Each state is still ultimately handling "modernization" in their own way. There's very little appetite for COTS for whatever reason, and little sharing of technical components between states.
If a motivated small company wanted to work with NASWA in a "not business as usual" approach, perhaps with 18F involved, I believe it could be done. Part of their role is to reduce duplicative efforts across states and try to establish best practices.
The problem of course is how many small companies are knowledgeable about the UI IT systems, and can put together a strong proposal? It's a bit chicken and egg. Yes, NASWA could push this harder if they really wanted to, but it's hard to manage a consensus oriented organization.
(I was not implying NASWA was going to build things themselves...though if I were king, I would have them develop an open source UI platform, and then give it to the states to customize for their individual scenarios. Companies could compete on how well they make those customizations, and support contracts. Of course the trend seems to be going in the opposite direction, unfortunately... c.f. VistA -> Cerner).