package qemu-kvm 0.13.0+noroms-0ubuntu12 [modified: usr/share/man/man1/qemu-user.1.gz] failed to install/upgrade: trying to overwrite '/usr/bin/qemu-ppc64', which is also in package qemu-user 0.13.50-2011.02-0-0ubuntu1

Thanks for reporting this bug and helping to make Ubuntu better. Indeed, qemu-ppc64 is being installed both by qemu-user and qemu-kvm. I've marked this low priority since (at least here in my test) the package does install successfully and is usable.

from duplicate:

roaksoax@shift:/var/cache/apt/archives$ dpkg -c qemu-kvm_0.13.0+noroms-0ubuntu15_amd64.deb | grep system-ppc64
-rwxr-xr-x root/root 3440880 2011-02-11 16:32 ./usr/bin/qemu-system-ppc64

roaksoax@shift:/var/cache/apt/archives$ dpkg -c qemu-system_0.13.50-2011.02-0-0ubuntu1_amd64.deb | grep system-ppc64
-rwxr-xr-x root/root 3829560 2011-02-07 16:04 ./usr/bin/qemu-system-ppc64
lrwxrwxrwx root/root 0 2011-02-07 15:59 ./usr/share/man/man1/qemu-system-ppc64.1.gz -> qemu-system.1.gz

From term.log:
Elaborazione dei trigger per python-support...

Si sono verificati degli errori nell'elaborazione:
 (error during installation of)
 /var/cache/apt/archives/qemu-kvm_0.13.0+noroms-0ubuntu15_amd64.deb

Log ended: 2011-02-15 17:42:59

Also the update still not installable at today, see attached screenshot

This bug was fixed in the package qemu-kvm - 0.14.0~rc1+noroms-0ubuntu1

---------------
qemu-kvm (0.14.0~rc1+noroms-0ubuntu1) natty; urgency=low

  [ Serge Hallyn ]
  * Merge qemu-kvm 0.14.0-rc1
  * removed all rom's
  * removed tests/pi_10.com as it's binary data
  * removed 697197-fix-vnc-password-semantics.patch in favor of upstream fix
  * removed caps-lock-key-up-event.patch - upstream commit
    9a121a2fbf88dd1bc869b1ac2449dc12c27cccfa is supposed to fix it
    - bdrung to verify
  * removed 1000-undo-earlier-static.patch
    - re-add if build fails - but we no longer do static build
  * removed 2000-vmmouse-adapt-to-mouse-handler-changes.patch, now upstream
  * removed arm patches - qemu-kvm now only offers x86 and ppc emulation
    - qemu-user provides armel
  * kvmtrace_format is now shipped with different tree.

  [ Dustin Kirkland ]
  * Re-roll tarball, adding ~rc1 to version, so that the official GA release
    will supercede these rc's
  * debian/control: bump standards versions, remove redundant depends on
    adduser, update section to misc
  * debian/rules: drop qemu-system-ppc64 from the build, as this is in
    qemu-linaro now, LP: #717690
  * debian/copyright: embed the BSD license, per lintian

  [ Steve Langasek ]
  * debian/rules: drop the binfmt-misc handling; we're not building any
    static user binaries from this source, so this is just noise.
  * debian/rules: $INSTALL_PROGRAM is never set, so modifying it is
    pointless. Delete this as well.
  * build qemu-kvm package on all archs; this is the authoritative package
    for x86 system emulators, so we only have to deal with the bios
    dependencies in one place.
  * don't run 'make install' in kvm/libkvm directory, this is a no-op anyway.
 -- Serge Hallyn <email address hidden> Mon, 14 Feb 2011 07:50:16 -0600

Awesome guys
Installed just now.
Many thaks
Fabio