Debian Unstable means actually packages are tested according to Debian Policy: *www.debian.org/social_contract
the packages are indeed stable are in the way to the stable distro via etch,testing distro.really unstable packages can be found in
*packages.debian.org/experimental/
yes they may be a little late in few packages to get into the distro.for eg earlier they didnot included Xorg as default X fast as Ubuntu did coz they waited Xorg to release modularised DRI.
nyways Ubuntu is also a great distro.
But Debian Community is purely FLOSS peoples work into making that Distro better.