I spotted the old roadmap posts and did a quick read through it. It mentions using Exim rather than Postfix but the install text in the tarball says to install Postfix/Courier/et al. Did the roadmap plan change back to Postfix?
Also, the install text file in the tarball for Debian is still using "apt-get install xxx". Current Debian instructions (as of Etch) suggest always using aptitude from now forward. Aptitude command line is essentially the same as apt-get --- "aptitude install xxx".