>>> 1. fetch the initial pkgsrc.tar.gz for a given branch ? I know I can
>>> get ftp://ftp.netbsd.org/pub/NetBSD/packages/pkgsrc.tar.gz.
>>> But is there any official pkgsrc-BRANCH.tar.gz to be fetch (rather
>>> than pkgsrc and then "cvs up -rBRANCH") ?

>> I think you can use [1] as the initial branch tarball of pkgsrc and
>> [2] as the _updated_ branch tarball for the same branch:
>>  [1]: ftp://ftp.netbsd.org/pub/pkgsrc/2005Q1/pkgsrc-2005Q1.tar.gz
>>  [2]: ftp://ftp.netbsd.org/pub/pkgsrc/2005Q1/pkgsrc.tar.gz

>  erf... I didn't see them when I browsed the FTP server.
>  sorry & thanks !

No problem :)

>  the update of those tarballs are daily ?
>  or only when a change is made to the source tree ?
>  or less often ?

As i can see, it seems to be updated daily (with or without new commits
in the pkgsrc tree) according to the timestamp of the corresponding file
on the FTP server, but i may be wrong here (correct me if i made some
mistake please).

-- 
-jpeg.