The a2ps default of printing to the default printer is the upstream default and documented in the upstream info file, so I think that changing the Debian version to behave differently would be surprising. However, I agree that the man page doesn't document this very well.
Here is a patch to fix that.
#! /bin/sh /usr/share/dpatch/dpatch-run ## 19_better_d_docs.dpatch by Russ Allbery <[EMAIL PROTECTED]> ## ## All lines beginning with `## DP:' are a description of the patch. ## DP: Better document the default output and the -d option. ## DP: Addresses Bug#193530 @DPATCH@ diff -urNad --exclude=CVS --exclude=.svn ./src/main.c /tmp/dpep-work.VxVNkZ/a2ps-4.13b/src/main.c --- ./src/main.c 2005-07-30 17:00:19.622678976 -0700 +++ /tmp/dpep-work.VxVNkZ/a2ps-4.13b/src/main.c 2005-07-30 17:00:40.252542760 -0700 @@ -656,7 +656,8 @@ fprintf (stream, _("\ Usage: %s [OPTION]... [FILE]...\n\ \n\ -Convert FILE(s) or standard input to PostScript.\n\ +Convert FILE(s) or standard input to PostScript. By default, the output\n\ +is sent to the default printer. An output file may be specified with -o.\n\ \n\ Mandatory arguments to long options are mandatory for short options too.\n\ Long options marked with * require a yes/no argument, corresponding\n\ @@ -781,7 +782,8 @@ --version-control=WORD override the usual version control\n\ --suffix=SUFFIX override the usual backup suffix\n\ -P, --printer=NAME send output to printer NAME\n\ - -d send output to the default printer\n")); + -d send output to the default printer\n\ + (this is the default behavior)\n")); sputc ('\n'); sfputs (_("PostScript:\n"));
-- Russ Allbery ([EMAIL PROTECTED]) <http://www.eyrie.org/~eagle/>