Looking at OpenFlash Chart v2. They have support for barChart animations. I was looking for ways of using that with ofcgwt and seems that the on-show attribute was missing. All I did is incorporate an onshow for the BarChart element and seems like a good addition to your framework. I included delay and cascade parameters as well.

http://teethgrinder.co.uk/open-flash-chart-2/bar-chart-on-show.php