When you turn Symmetry on while components are selected, Maya automatically selects the appropriate mirrored components. There is also now a HUD element that displays the current axis of symmetry when one is active.
In addition, symmetry support has been expanded to the following tools:
You can now use the new Auto Seams command to automatically select or cut appropriate seams for your meshes or UV shells. This saves you from having to select and cut edges manually, while also ensuring that edges aren't missed accidentally. See Auto Seams.
The new Curve Warp deformer allows you to quickly connect a mesh to a curve to drive a variety of deformation effects. It is similar to motion paths but offers greater customization with a more streamlined workflow. See Curve Warp deformer.
A new set of Sculpt Target Tools have been added to specifically support Shape Authoring workflows. These include:
The Bevel Options have been updated with new attributes related to Depth, Mitering, and Chamfer to give you more precise control over a Bevel operation. See Bevel Options.
You can now choose the direction in which to bridge source and target edges/faces when using the Bridge command. See Bridge Options.
Select the new Isolated Components option (Mesh > Cleanup) before performing a mesh cleanup to remove orphaned components that are created during modeling operations. See Cleanup Options.
When using the Combine command to combine separate meshes into one, you can now specify where the pivot for the newly combined mesh appears. See Combine options.
Bake Pivot Orientation has been renamed to Bake Pivot (Modify > Bake Pivot). By default, Bake Pivot now bakes the edited pivot's position and orientation, but the new Bake Pivot Options also lets you bake only position or orientation. See Modify > Bake Pivot.
Improvements to the Extrude command's thickness algorithm produce more predictable results when using extrude to generate thickness on a mesh.
Showing and hiding components now functions like hiding and showing objects. See Show or hide components.
Mirror Geometry and Mirror Cut have been consolidated into a single Mirror command that supports a new and more robust mirroring workflow. See Mirror Options.
Nudge UVs now supports an extra decimal place for more fine-tuned adjustments. See Nudge shells and components in the UV Editor.
The minimum cursor distance required to highlight a component via Preselection Highlight can now be modified in the Selection Preferences. It has also been improved with better accuracy, particularly when trying to select components that are behind other components in wireframe mode or when the cursor is hovering just outside a mesh. See Highlight components before selecting them.
The Conform operation now supports projection along normals. The new Along Normals option is selected by default in the Conform Options (Mesh > Conform), projecting the vertices of the selected object onto the live surface along the direction of its normals.
The polyShape node now displays the current global subdivision method in parentheses next to the Subdivision Method attribute. This saves you from having to go to the Preferences when deciding how to set this attribute. See Smooth Mesh node.
You can now adjust the transparency and color of wireframes displayed when sculpting a mesh. See Sculpting Tool Settings.
Add Divisions is no longer limited to a maximum of four division levels. See Add Divisions Options.