Some protocol updates were merged and will come in force soon.
Since 20 March, 2016:
New transaction type, allowing people to use one-time public keys for sending/redeeming the coins. This is much better in terms of privacy, in comparison with standard addresses.
https://github.com/novacoin-project/novacoin/blob/master/doc/MalleableKeysRawTx.txt (raw tx example for testnet)
The sendtoaddress, sendfrom and sendmany RPC calls have been adjusted to work correctly with the one-time key pairs. There are also new RPC calls, such as newmalleablekey, adjustmalleablepubkey, adjustmalleablekey and listmalleableviews. Documentation is going to be updated a bit later.
Since 20 April, 2016:
OP_CHECKLOCKTIMEVERIFY and OP_CHECKSEQUENCEVERIFY support.