MongoDB Version 3.0 is about to release in March 2015. They have added lot of new features to MongoDB database.
MongoDB 3.0 New Features:
Pluggable Storage Engine API
MongoDB 3.0 introduces a pluggable storage engine API that allows third parties to develop storage engines for MongoDB.
Increased Number of Replica Sets
MongoDB 3.0 supports upto 50 Replica Set Members.
New Query Introspection System
This new Query Introspection System is used to provide an improved output format and a finer-grained introspection into both query plan and query execution.