This small patch changes many cursors in the View3D editor. My hope is that this patch can be tested and then serve as a starting point for further changes and tweaks.
The major problem this patch addresses is that Edit Mode defaults to using a cross cursor, and in almost all cases this is not the best cursor. In fact, our major goal with mouse cursors is to set them per-tool, not per-mode. In most cases while editing mesh you can select more than a single vertex, but also edges, faces, and sometimes much more. A cursor designed for selecting a single vertex is less than ideal and actually covers up what you trying to select in many cases. This is the current consensus of the core developers and UI team.
Currently the View3D editor checks to see if it can set the cursor based on the current tool. If it cannot it defaults to WM_CURSOR_EDIT if in Edit Mode, or to WM_CURSOR_DEFAULT if not. This patch makes it so the default (if not set by tool) is WM_CURSOR_DEFAULT (the OS-supplied pointing cursor).
With this change there are a few tools that should not be default pointer. So this patch makes the "Measure" tool use the cross cursor, as it does now. Similarly "Lasso Select" is also set to use cross cursor. However, "Circle Select" tool is set to use NONE for cursor. This is because that tool draws a wide circle that represents the area of selection. While selecting with this tool the center has no importance at all and it is only the circle outer edge that matters.
This patch also makes it so the Navigate Gizmo (the widget with axes balls at the top right) will use the default pointer when hovering over it. The Cross cursor covers up the Axis labels too much.