A significant new release of the Bitcoin-Qt and Bitcoind clients from Bitcoin.org, v0.7.0, is now available for download.
This v0.7 release includes a number of new features, performance improvements and bug fixes and is the first major feature release since the v0.6 release nearly six months ago.
A subset of the improvements includes:
Calls for better privacy are answered with Tor hidden service support.
IPv6 support.
URI Handling (click on bitcoin address, address and amount are entered for you.)
Lower CPU usage during block downloads.
Optional method to load blockchain from a local file.
Raw transaction API (Full access to the blockchain data)
Better translations (Language support)
While it is recommended to back up the wallet.dat before performing this upgrade, the update will not overwrite an existing wallet or blockchain database.
http://bitcoin.org/releases/2012/09/17/v0.7.0.html
http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.7.0
http://bitcointalk.org/index.php?topic=110243.0
Also new since the last major release are how alternatives to the Bitcoin.org reference implementation client are featured on the Bitcoin.org Clients page. The alternatives for the desktop include:
MultiBit: A secure, lightweight, international Bitcoin wallet for Windows, MacOS and Linux. No blockchain download required. Armory (Alpha): An open-source wallet-managment platform for the Bitcoin network.
Electrum: A lightweight Bitcoin client, based on a client-server protocol. No blockchain download required.
Coming in the next significant release to bitcoin will likely be the use of LevelDB for faster access when the client reads or writes to the blockhain, and “ultraprune” which will result in a much lower storage requirement to hold the blockchain.