Viewport 2.0 Improvements in the Extension for Maya 2013:

• Improved mipmapped texture filtering allowing for crisp closeup textures and smooth distant textures
• VP2 now supports floating point precision allowing for improved accuracy in large scenes and objects far from origin
• Performance improvements in static and animated character scenes
• Stability improvements
• Component level isolate select is supported
• Complete support for viewport display filtering
• Support for mentalray viewport UI in VP2: IBL, FG & Photon Map Vis and Custom Area light shapes (with lightshape visiblity)
• Improved NURBS tessellation quality and performance
• Support for high dynamic range EXR textures in VP2
• Cast and Receive shadow flags are supported
• All viewport modes supported (All, none, use selected) 
• Display Layer and object level templating supported
• Improved Nurbs curve and trim surfaces support
• Construction plane support
• Skinned vertex influence coloring

Shading support:

• High Fidelity VP2 Rendering: 
• Default color input on native shaders
• Single component inputs 
• Shading switch
• 2d placement noise
• Layered texture / shader
• Multiply divide 
• Clamp
• Ramp 
• Fractal
• Snow
• plusMinusAverage
• multDoubleLinear
• vectorProduct
• addDoubleLinear
• Condition
• Contrast
• setRange
• Noise
• Bulge
• Cloth
• Mountain
• remap HSV, color, value
• Gamma

Baked:

• Projection mapping
• Movie
• Mandelbrot
• Ocean
• Water
• Cloud
• Wood
• Brownian
• Crater
• Granite
• Leather
• Marble
• Rock
• solidFractal
• Stucco
• VolumeNoise