I use JSON extensively for my projects.
I use jsRender and jsViews to consume the JSON on the client (makes maintenance much easier and is much leaner than building the pages on the server).
When using a DW recordset...I have to comment out the fetch line (this unfortunately breaks the widget).
I then insert a few lines of code to generate the array and then encode it as JSON (no problem). I also generate hierarchical JSON as well.
Since, Adobe is removing the db functionality from CS7...I am guessing you will build your own tools...thus a perfect time to build something full featured.
Note: I am only interested in Data Assist supporting this.