Chuck Clark Sensei was gracious enough to send me a couple of his videos and I have to say that his Randori video is a wonderful example of how to start blurring the roles of uke and nage. They can be obtained at:
Also, Robert Brynner Sensei put out a very useful set of videos on precisely this topic. I would also recommend these! They are available at:
Saotome Sensei has a new DVD called Oyo Henka which is also about developing the ability to spontaneously adjust to changes in uke's attack. This is available from ATM at:
You'd have a lot to work on if you got a couple of these videos.