"This most notable new feature of APT 0.5 is the automatic
configuration of build-dependencies for source packages via apt-get
build-dep which will download a source package, satisfy build
dependencies, and build it. This will ease the workload of many
unofficial back-porters as well as those who like to tweak
otherwise standard setups of packages that may not otherwise take
full advantage of other optional components."
"Not that back-porters that have become prominent in the
Potato-using community need to continue much of their work once APT
0.5 makes a stable release as APT will incorporate a pinning
feature. This will to allow users for the first time to easily
install packages from another tree different from the one that is
installed on their box. For example, apt-get install
mozilla/unstable will installs unstable's version of mozilla onto a
testing or stable system."