Couple of updates:

- Improved synchronisation to prevent double spends from occurring when submitting a high volume of transactions.
- Merchant API now supports compressed private keys.
- Fee parameter added to send API.
- Ability to supply a private key directly to the API to send funds without needing a My Wallet account.
- Improvements to Bitcoind status monitoring (https://blockchain.info/status_check). Recently two nodes feel behind causing an error "cannot find map prev tx" error when trying to submit certain transactions.