Debian7 Live (wheezy), from the Debian Live Systems project, has been released...

http://lists.debian.org/debian-live/2013/05/msg00014.html

Images for i386 (32-bit) and AMD (64-bit) architectures are available for download from...

http://live.debian.net/cdimage/release/stable/

With desktop choices of gnome3, kde, lxde, and xfce, their .iso files range in size from 854MB to 1.2GB. Rather than make a bootable DVD, you may wish to use dd to make a bootable USB stick from the iso image, see...

http://www.debian.org/CD/faq/#write-usb

If you want your USB stick to have a persistence file, then the fun of doing so appears to start here...

http://forums.debian.net/viewtopic.php?f=30&t=91849

...and carries on here...

http://live-systems.org/manual/current/html/live-manual.en.html#186