Knowing your user and what they want is a good thing; basing design decisions exclusively on this knowledge can hurt innovation and kill off surprise. Couple of interesting videos on this subject:

1) Bruce Sterling @ The Interaction Design Association conference who says, “”Too much sympathy for your characters makes you a crap novelist” (via Influx Insights)

http://vimeo.com/20305063

2) Guy Murphy, Worldwide Planning Director at JWT London talking about how inspiration can come from any part of the design process not just consumers (via Futurelab)