I need pipelines and file redirection to work, and last time I looked these two were badly broken by file associations,

Hm. For as long as I've been using perl--7 years, 5.6.1 & NT4 sp1--input & output redirection and output pipelining have all worked fine using file associations:

c:\test>type echoit.pl
#! perl -sw
use strict;

print while <>;

c:\test>echoit <junk.dat
jim  14
john 23
ernest 38
matilda 43
jim 34
ernest 27
john 44
matilda 22

c:\test>echoit <junk.dat >junk.out

c:\test>type junk.out
jim  14
john 23
ernest 38
matilda 43
jim 34
ernest 27
john 44
matilda 22

c:\test>echoit <junk.dat | find "j"
jim  14
john 23
jim 34
john 44
[download]

The only (minor) inconvenience is for input piping you need to prefix the script name with 'perl':

c:\test>type junk.dat | perl echoit.pl
jim  14
john 23
ernest 38
matilda 43
jim 34
ernest 27
john 44
matilda 22
[download]

But that's more than compensated for by not having to deal with the .bat nanny prompt:

Terminating on signal SIGINT(2)
Terminate batch job (Y/N)?
[download]

And far outweighed by not having to remember to re-pl2bat if you edit the thing.

But most of all, being able to add perl switches to the command line:

perl -c script.pl
perl -d:Trace script.pl
perl -X script.pl
[download]

And finally, use perl's built-in switch parsing:

script -S=this -T=that
[download]