Last year, Jared Spool wrote an essay about a disruptive intranet redesign in which he used the analogy of finding your well lived-in home entirely changed on waking up one morning (Designing Embraceable Change). In it, he discusses how to make it easier for people to embrace changes in their information spaces:
To design for embraceable change, the design team has to be well aware of the existing Current and Target Knowledge points, as well as the new points. Field studies are the ideal technique for learning the existing points, whereas usability testing will give a detailed understanding as to whether the new design has an acceptable knowledge gap. These two techniques are essential for any team who needs to tackle this difficult problem.