You can view normal maps (for example, those you create using the Transfer Maps tool) in Viewport 2.0 in textured mode. Press 6 to switch to textured display mode.
Display your normal map in tangent space map or object space
The existing bump2d nodes in your scene are found in the Utilities tab of the Hypershade Browser panel. See Build and create materials using the Hypershade.
To select the bump node for the shader network currently assigned to your object, select the object, then select Graph > Graph Materials on Selected Objects from the Hypershade menu. Select the bump2d node in the resulting graph in the Hypershade work area panel.
In the Transfer Maps editor, you have the option of baking the map in Tangent space or in Object space. For more information regarding tangent space versus object space, see Object space, world space and tangent space.
However, when you bake a normal map in the Transfer Maps editor, Maya automatically recognizes the map space that you choose and displays the normal map correctly in the viewport.