Comment 5 for bug 736227

If you REALLY want to make sure it'll never get in Kubuntu/Xubuntu (it's in universe so it can't be included on an Ubuntu CD), you can but it's really not necessary as software-center doesn't depend/recommend/suggest it.

It's just a feature that'd appear if the package happens to be installed but not something that'll happen in any case by default outside of Edubuntu where we explicitly seed "qtnx" so we have the feature.