There are 87 NEW system variables in AutoCAD 2007, thus Civil 3D 2007. I am confident that a list will help some so here they are:
System Variable - Description
3DDWFPREC - Controls the precision of 3D DWF publishing.
CAMERADISPLAY - Toggle camera objects display in the current drawing.
CAMERAHEIGHT - Stores the default height for newly created camera objects.
CLEANSCREENSTATE - Stores a value that indicates whether the clean screen state is on (read-only).
CMATERIAL - Sets the material of new objects.
CSHADOW - Sets the shadow display property for a 3D object.
DASHBOARDSTATE - Determines whether the Dashboard window is active or not.
DEFAULTLIGHTING - Turns default lighting on and off.
DEFAULTLIGHTINGTYPE - Specifies the type of default lighting.
DIMARCSYM - Controls display of the arc symbol in an arc length dimension.
DIMFXL - Sets the total length of the extension lines starting from the dimension line toward the dimension origin.
DIMFXLON - Controls whether extension lines are set to a fixed length.
DIMJOGANG - Determines the angle of the transverse segment of the dimension line in a jogged radius dimension.
DIMLTEX1 - Sets the linetype of the first extension line.
DIMLTEX2 - Sets the linetype of the second extension line.
DIMLTYPE - Sets the linetype of the dimension line.
DIMTFILL - Controls the background of dimension text.
DIMTFILLCLR - Sets the color for the text background in dimensions.
DRAGVS - Sets the visual style while creating 3D objects.
DWFFRAME - Determines whether the DWF frame is visible and if it will plot.
DWFOSNAP - Determines whether object snapping is enabled for DWFs that are attached to a DWG.
ERSTATE - "Determines whether the External References window is inactive - active/visible or active/auto-hidden."
GRIDDISPLAY - Controls the display behavior and display limits of the grid.
GRIDMAJOR - Controls the frequency of major grid lines compared to minor grid lines.
GRIDUNIT - Specifies the grid spacing (X and Y) for the current viewport.
GTAUTO - Controls whether or not grip tools display automatically when selecting objects in 3D space.
GTDEFAULT - "Controls whether or not the 3DMOVE, 3DROTATE, and 3DSCALE commands start automatically when the MOVE, ROTATE, and SCALE commands (respectively) are started in a 3D view."
GTLOCATION - Sets the default location for grip tools.
IMPLIEDFACE - Controls the detection of implied faces.
INTERFERECOLOR - Sets the color of interference objects.
INTERFEREOBJVS - Sets the visual style for interference objects.
INTERFEREVPVS - Sets the visual style for the current viewport while using the INTERFERENCE command.
LATITUDE - Specifies the latitude of the drawing model.
LEGACYCTRLPICK - Specifies the keys for selection cycling and the behavior for CTRL + left-click.
LIGHTGLYPHDISPLAY - Controls whether light glyphs are displayed.
LIGHTLISTSTATE - Indicates whether the Lights in Model window is open or closed.
LOFTANG1 - Sets the draft angle through the first cross section in a loft operation.
LOFTANG2 - Sets the draft angle through the last cross section in a loft operation.
LOFTMAG1 - Sets the magnitude of draft angle through the first cross section in a loft operation.
LOFTMAG2 - Sets the magnitude of draft angle through the last cross section in a loft operation.
LOFTNORMALS - Controls the normals of a lofted object where it passes through cross sections.
LOFTPARAM - Controls the shape of lofted solids and surfaces.
LONGITUDE - Specifies the longitude of the drawing model.
MATSTATE - Indicates whether the Materials window is open or closed.
NORTHDIRECTION - Specifies the angle of the Sun from north.
OSOPTIONS - Automatically suppresses object snaps on hatch objects and when you are using a dynamic UCS.
PERSPECTIVE - Specifies whether the current viewport displays a perspective working view.
PSOLHEIGHT - Sets the default height for a swept solid object created with the POLYSOLID command.
PSOLWIDTH - Sets the default width for a swept solid object created with the POLYSOLID command.
PUBLISHALLSHEETS - Controls how the Publish dialog list is populated.
RENDERPREFSSTATE - Stores a value that indicates whether the Advanced Render Settings palette is open.
SHADOWPLANELOCATION - Controls the location of an invisible ground plane used to display shadows.
SHOWHIST - Controls the Show History property for solids in a drawing.
SOLIDHIST - Controls the default History property setting for new and existing objects.
STEPSIZE - Specifies the step size in current units when users are in Walk mode.
STEPSPERSEC - Specifies the number of steps taken per second when users are in Walk mode.
SUNPROPERTIESSTATE - Indicates whether the Sun Properties window is open or closed.
SUNSTATUS - Controls whether the Sun is casting light in the viewport.
TIMEZONE - Sets the time zone for a sun study.
UCSDETECT - Controls whether dynamic UCS acquisition is active or not.
VSBACKGROUNDS - Controls whether backgrounds are displayed in the current viewport.
VSCURRENT - Stores the name of the visual style applied to the current viewport.
VSEDGECOLOR - Sets the color of edges.
VSEDGEJITTER - Controls the degree to which lines are made to appear as is they were sketched with a pencil.
VSEDGEOVERHANG - Makes lines extend beyond their intersection for a hand-drawn effect.
VSEDGES - Controls the types of edges that are displayed in the viewport.
VSEDGESMOOTH - Specifies the angle at which crease edges are displayed.
VSFACECOLORMODE - Controls how the color of faces is calculated.
VSFACESTYLE - Controls how faces are displayed in the current viewport.
VISUALSTYLES - "Displays the Visual Styles Manager palette - allowing you to create and modify visual styles or apply a visual style to a viewport."
VSHALOGAP - Sets the halo gap in the visual style applied to the current viewport.
VSHIDEPRECISION - Controls the accuracy of hides and shades in the visual style applied to the current viewport.
VSINTERSECTIONCOLOR - Specifies the color of intersection polylines in the visual style applied to the current viewport.
VSINTERSECTIONEDGES - Specifies the display of intersection edges in the visual style applied to the current viewport.
VSINTERSECTIONLTYPE - Controls whether obscured lines are displayed in the current viewport and sets their linetype.
VSLIGHTINGQUALITY - Sets the lighting quality in the current viewport.
VSMATERIALMODE - Controls the display of materials in the current viewport.
VSMONOCOLOR - Sets the color for monochrome display of faces.
VSOBSCUREDCOLOR - Specifies the color of obscured lines in the visual style applied to the current viewport.
VSOBSCUREDEDGES - Controls whether obscured (hidden) edges are displayed.
VSOBSCUREDLTYPE - Specifies the linetype of obscured lines in the visual style applied to the current viewport.
VSOPACITY - Controls the transparency of faces in the current viewport.
VSSHADOWS - Controls whether a visual style displays shadows.
VSSILHEDGES - Controls display of silhouette curves of solid objects in the visual style applied to the current viewport.
VSSILHEDGEWIDTH - Specifies the width in pixels for display of silhouette edges in the current viewport.
VSSPECULAR - Controls the display of specular highlights on faces without materials in the current viewport.
VSSTATE - Stores a value that indicates whether the Visual Styles window is open.
ZOOMWHEEL - Allows users to toggle the behavior of mouse wheel zoom operations.