Since Debian 3.1 (sarge) was recently released Mon June 6, the package repositories have been unfrozen & we will soon see active development & new updated packages in the Debian repositories. So I hope to see X.org into Debian unstable (sid) in the next year. Also note that Knoppix developers rarely if ever use non-Debian stable/testing/unstable packages for the core of the distro. Some exceptions:
OpenOffice.org 1.1.x & 2.0 has always been non official build.
KDE 3.4.0 in Knoppix 3.9 was pulled from a experiemental repository of http://pkg-kde.alioth.debian.org/ but it was made by the offiical Debian package maintainers of KDE so technically it is a Debian package.
WiFi/802.11 drivers.