Following is a summary of the new features introduced by the 2014.1 release:

• Performance - the Chart and Gauge web parts now use the highly optimized Nevron Chart for .NET 2014.1 engine. This leads to performance improvements in nearly all charting types. Significant performance gains are experienced in all 3D charting types.
• Calculated Series - the Chart web part now has full support for Calculated Series. Calculated Series are line series that are attached to a master series and display a trendline or formula that is based on the master series values. In the 2014.1 we have added support for the following calculated series formulas:
  

Min
Max
Median
Cumulative
Sum
Average
Exponential Average
Root Mean Square
Standard Deviation
Bollinger Bands
Envelopes       
Simple Moving Average
Weighted Moving Average
Exponential Moving Average
Modified Moving Average
Median Price
Typical Price
Weighted Close        
Positive Direction Indicator
Negative Direction Indicator
Directional Movement Index
Average Directional Movement
Average True Range
Chaikins Volatility
Commodity ChannelIndex
Detrended Price Oscillator
Mass Index
Momentum
Momentum Division
Moving Average Convergence Divergence
Performance
Rate Of Change
Relative Strength Index
Stochastic Oscillator
TRIX
True Range
Williams % R

The calculated series also feature full control over their appearance, chart area, display on axes, data labels, data labels layout, markers, action and formula specific parameters. Take a look at the Values Data Groupings - Calculated Series topic for more info.

• Others Pie Group - the Chart web part now has built-it support for grouping pie slices that are below a certain value or percent in an "Others" group. The "Others" group label, appearance and action is also fully controllable. The "Others" group feature greatly increases the readability of pie charts with multiple small slices. Take a look at the Pie Chart topic for more info.