Install wine 1.4 on Debian Sqeezy (not tested)

Edit your /etc/apt/sources.list by adding the following:

deb http://main.mepis-deb.org/mepiscr/repo/ mepis85cr main
Mepis is a Linux distro based on the stable branch of Debian, but it comes with more updated binaries (wine included).

Edit your /etc/apt/preferences file (or create it if it doesn’t exist):

Package: *
Pin: release n=squeeze
Pin-Priority: 900
Package: *
Pin: release n=mepis85cr
Pin-Priority: 200
This will allow you to choose from which repository to install new packages. By default the squeeze packages will be used.

Now from a console type:

:~$ sudo apt-get update
:~$ sudo apt-get install wine/mepis85cr
The /mepis85cr next to apt-get install will choose the packages from Mepis instead of Debian.

Enjoy your updated wine version!