Do you want a bug open on this one, or just push it? I think it is small enough just to push it. Get our fearless leader to comment, but unless someone wants a bug opened, I'd just push it if all give the nod.
I will push changes for the few *.desktop files discussed.
As I mentioned, the core problem is not OnlyShowIn=TDE but the XDG_* environment variables. In the broader scheme, we have no remedy for getting other environments to source /opt/trinity in the XDG_* environment variables.
In distros that use /etc/profile.d, the solution is to ensure a script is installed (could be nothing more than the normal trinity.sh script). For the distros that don't use /etc/profile.d, such as Debian, I don't know how to ensure XDG_* variables are modified to recognize /opt/trinity.
As I mentioned, when KDE4 is concurrently installed with Trinity, the result will be a menu mess one way or another, unless we provide distro maintainers a more organized menu structure to handle the KDE4/Trinity overload.
Some might ask, why would users install Trinity and use a different environment? Many users prefer window managers rather than full desktops, but prefer a selection of apps from the full desktop environments. Many systems are multi-user, and the various users select what to run. In those instances, all options must be installed.
There is a growing restlessness in the KDE4 community for PIM apps that do not rely on the akonadi/nepomuk foundation. Trinity PIM apps could fill that role, but without modifying the XDG_* environment variables, the apps won't be found in non-Trinity desktops.
Darrell