In a few of my previous interactive applications, namely Digg Explorer and the Race Results Analyzer, I have used small 'data objects' that get smoothly animated between different locations. Sometimes the set of data objects represent a data graphic - a pie chart or histogram for example.
I have just come across a research paper and video by Jeffrey Heer and George Robertson where they investigate the effectiveness of animated transitions in statistical data transitions. Their conclusion was that animated transitions can significantly improve graphical perception. The video is high quality and explains the ideas and results very well.
Note that this research did not use multiple constituent data objects as in my applications but the conclusion is likely valid in this context as well.