1. Multi-value attributes support
Just set an array of values for an attribute and that's it.
eg:
my_object.tags = ['a', 'b', 'c']
2. Sharding
Sharding allows you to partition your data for a single class across multiple domains allowing increased write throughput, faster queries and more space (multiply your 10GB per domain limit).
You can see some example classes using sharding here: