libxbps:
 - transaction: avoid fetching the whole pkg when updating and only fetch
   modified files from target pkg.
 - remove-obsoletes: remove obsolete links, not just dangling links.
 - properties: (update-first) still unimplemented.

xbps-bin:
 - Improve help output and add description at the same line than target.

xbps-create:
 - Move all configuration files to <prefix>/share/<pkgname>/conf/<cffile>.
 - Add -i --installed option to create binpkg from an installed version.

xbps-repo:
 - Improve help output and add description at the same line than target.
 - Add support to sign with PGP or RSA the repository index files.
 - Add requiredby support to pkg's dictionaries in repository's index,
   to know reverse deps from remote repos.

All:
 - Maybe merge xbps-bin(8) and xbps-repo(8) onto xbps(8).

Issues listed at http://code.google.com/p/xbps/issues/list

Surely more stuff...