Room layout ideally should be an extension of the learning. Adaptable designs allow for differentiation. They avoid a repetitive setting and instead customize the space for lessons. Redecorating enlivens the children's experiences and provides flexible room for technology or discussions. Feng shui harmony translates to the classroom, as the arrangement matters.
When students enter a classroom and encounter a new configuration, they appreciate both the unpredictability and the predictability. They like the change, even if unexpected, because it validates the importance of their daily scene. Students begin to anticipate the learning by the day's arrangement, which itself is a decoding, thinking skill. Keeping a classroom fixed is not inherently bad, but it does suggest that information delivery might be fixed, too. Not updating a design is like not changing a bulletin board or not refreshing a homepage -- certainly not a crime, but not ideal either.
Update: Classroom Architect is a free, easy, interactive web tool to design sample layouts and move furniture in a virtual floor plan for your classroom.