This new version of Debian includes various interesting features such as multiarch support, several specific tools to deploy private clouds, an improved installer, and a complete set of multimedia codecs and front-ends which remove the need for third-party repositories.
Multiarch support, one of the main release goals for "Wheezy", will allow Debian users to install packages from multiple architectures on the same machine. This means that you can now, for the first time, install both 32- and 64-bit software on the same machine and have all the relevant dependencies correctly resolved, automatically.
The installation process has been greatly improved: Debian can now be installed using software speech, above all by visually impaired people who do not use a Braille device. Thanks to the combined efforts of a huge number of translators, the installation system is available in 73 languages, and more than a dozen of them are available for speech synthesis too.
In addition, for the first time, Debian supports installation and booting using UEFI for new 64-bit PCs (amd64), although there is no support for "Secure Boot" yet. This release includes numerous updated software packages.