WordPress recently updated the statistical charts and I got a request from a user to update the WordPress Stats Windows Gadget to reflect the changes as well. I have released a new version of the Windows Gadget here which includes the following changes.
Column Chart
The option of selecting either a line or a column graph as pictured above.
Updated Tooltip
The tooltip that appears when hovering over a data point is much more aesthetically pleasing and allows you to include the published posts when viewing the statistics grouped by day.