Debian official releases are more rare than releases of other distributions, but tend to matter less to users. Judging by the second release candidate, Debian 6.0 will be no exception. In other words, the new release should deliver the usual ultra-reliability, and serve as a solid basis not only for Debian itself, but also the countless other distros that will depend upon it, including Ubuntu and Linux Mint.
Debian releases tend to matter less to users because, with the exception of system administrators or the security-conscious, few users stay with the Stable release. Most tend to pick and choose new features from the Testing or the Unstable repositories, which, despite their names, are generally stable enough for most purposes. For such users, stable releases are just another upgrade, interesting chiefly as a snapshot of Debian policy and development over the last few years -- and that is as true of Debian 6.0 as its predecessors.
For anyone who follows the Debian mailing lists even desultorily, Debian 6.0 can be seen as the outcome of two longstanding debates.
Debian has always supported more computer architectures than most distributions. Debian 6.0, for instance, officially supports eight, including 32- and 64-bit versions, SPARC, and PowerPC. With this kind of extensive coverage, it seems a sign of the times that Debian no longer officially supports the HP PA-RISC architecture, and has replaced the ARM architecture with the ARM EABI.
The dropped architectures may continue to be developed, but their change of status indicates that the Debian project as a whole no longer includes them in the list of what must be ready before an official release -- in other words, that they are no longer important to users.
Unofficially, Debian 6.0 is also including a GNU/kFreeBSD port, marking the first time that a GNU/Linux distribution has supported a non-Linux kernel.
Even more importantly, Debian 6 defaults to a free kernel. That means that the standard proprietary firmware drivers are not included in the standard kernel, and have been moved to the non-free section of repositories -- a typical Debian solution that lets it join the ranks of free distributions, while letting users make up their minds on the degree of freedom they want in their installations. Those who want or need the proprietary firmware can either opt to install it during installation, or else watch for builds that include them.
On the technical side, Debian 6.0 puts to rest one longstanding myth while perpetuating another.
The myth that is put to rest is that Debian is hard to install. While true a decade ago, that myth has been coming less and less true with the last few releases, but, in Debian 6.0, the distribution now has a polished installer that gives users the opportunity for fine-tuned control while remaining simple enough that even new users should have no trouble understanding what they are doing.
Like earlier versions, this installer clearly lays out its stages, and allows users to retrace their steps as necessary -- or even open a terminal if problems cannot be solved any other way. However, the latest version of the installer has improved explanations of steps and online help, as well as defaults that should work for most users. Moreover, it is backed by the most comprehensive release notes that I have ever seen.
With this support, the installer can offer an impressive set of choices for those who want them. Packages can be selected according to the intended function of the installation -- for instance, desktop environment, or file server or laptop. While dropping ReiserFS, partitioning includes both a choice of ext2, ext3, ext4, btrfs, JFS and XFS filesystems (sensibly defaulting to ext 3 as the best combination of mature features and stability), and multiple partitions (either placing /home on a separate partition, or sub-dividing a drive into root, /home /usr, /var, and /temp partitions.