Vertical, Hierarchical Worksheet Tab Column at the right instead of Worksheet tabs at the bottom
Instead of having worksheet tabs at the bottom of the viewing window, put the worksheet tabs in a column to the far right. This way you can see more tabs on the screen at a time and use longer more descriptive worksheet titles. This would make worksheets much easier to navigate and organize. Furthermore it would be great to make the tabs able to be hierarchical as in the attached example where Schedule 4 has a drop-down arrow that that reveals tabs for sub-schedules a, b and c. Of course please keep all of the fill color options for the tabs. Also allow the user to adjust the column width of the tab column. Would be great to see a worksheet description or comments when hovering over the tab.