I just tried installing LibreOffice 4.1 in my openSUSE 12.3 x64 OS and it worked like charm.
Unfortunately LibreOffice 4.1 is not yet available at software.opensuse.org
here I am updating quick install steps. I am using KDE in my case.

- Download LibreOffice.tar.gz from LibreOffice Productivity Suite Download
- Extract in a folder
- Go inside the dir
- Now go inside RPMS dir
- Fire command "sudo rpm -i *.rpm"

And that's it. It takes barely 4 minutes to install LibreOffice 4.1.
I got some error but LibreOffice 4.1 is working fine without any issue.
And it installs separate copy. It keeps older versions as it is.