- General Purpose – m3.xlarge and m3.2xlarge.
- Compute-optimized – c3.xlarge, c3.2xlarge, c3.4xlarge, and c3.8xlarge.
- GPU – g2.2xlarge.
- Memory-optimized – cr1.8xlarge.
- Storage-optimized – i2.xlarge, i2.2xlarge, i2.4xlarge, and i2.8xlarge.
More info here – http://aws.typepad.com/aws/2014/03/new-instance-types-for-amazon-elastic-mapreduce.html