Don Norman reaches the conclusion that design research does not really result in breakthrough products. Pretty good read and this jives with my own experience with product development. Product research seems to be working for incremental developments- Integrative/Design thinking though seems to be far more potent in coming up with something new.
I have been on a few research trips and they ground your ideas really fast. You quickly realize what ideas may or may not be crap. They give you fuel for more ideas. But I get a lot of fuel from simply keeping my eyes and mind open (well..trying to anyway) My own experience is that you need to stew for a little while. That means new ingredients need to be added to the mix all the time. You need to be trying multiple approaches to product development- and that unfortunately a bunch of cool ideas will pop up on completely unrelated projects and tick off designers and managers when you suggest something that might delay a project with those good ideas :)