Not column charts. I've seen plenty of simple ones for that. I'm using a floating bar chart with custom bar rendering to give the user an option of fill color.
Right now the issues I'm facing are:
-min/max values aren't being properly set by the chart
-padding doesn't stay consistent with larger date ranges
-dateTimeAxis labels do not wrap over a year change properly if only the month/year are scaled in the axis labels. (for example, if the label units are scaled to month/year (2/10 and 12/09 as end and start dates respectively), then the labels go from 2/10 (from origin of axis) to 12/09 instead of the other way around, the proper way.
If these are known bugs in Flex 4 Beta 2, please let me know! If you have any ideas of how I might solve these problems, please let me know!