Key Features:

Adds support for more low power sensors
10 sensors including support for light, digital microphone, magnetic sensor, humidity, pressure, accelerometer, gyroscope, magnetometer, object temperature, and ambient temperature
Lower power
Longer battery life from your coin cell and enabler of battery-less applications
High-performance ARM Cortex M3 (CC2650)
Cloud connectivity
Access and control your SensorTag from anywhere
Seamless integration with mobile apps
DevPacks allows you to expand the SensorTag to fit your designs
Interchangeable between all SensorTag types
Complete development system
Code Composer Studio compiler license included
Extreme flexibility for IoT applications
Enable ZigBee or 6LoWPAN through a firmware upgrade

Relevant Resources:
Understanding Wireless Connectivity in the Industrial IoT