I would like to have more than one gene/row label displayed. This would be useful for showing things like gene symbol and for instance different affy_probeset names at a same time. Or for both the miRNA target mRNA expression and which miRNAs are targeting that mRNA. There are number of situations where this would be useful. It would help build heatmaps that display more information.
Maybe you could have in the pull down menu a tick that would enable to select multiple labels instead of the dot for selecting just one.