Lubuntu 12.04 is not a long-term-support release. That's mostly due to a lack of manpower.
But I don't use Lubuntu on my machine, I use LXDE over stock Ubuntu 12.04 LTS. So my question is:
In the next five years, will there be security updates and bug fixes for LXDE-packages such as Openbox, PCmanFM and LXsession? Or does the "LTS" in 12.04 LTS only include stock Unity packages?
I guess this question is just as relevant for any other DE out there.
If you look at the lxde packages (I chose lxde-common) you'll see:
The hint you're looking for is the
Section: universe/x11
. This tells you the package is in Universe:This means that it's community-maintained, and since the people who maintain LXDE announced that they won't be supporting it then basically you can't be guaranteed that it will be supported for as long as you need it.
If you do an
apt-cache show unity
you'll see a line that says:This means that the package is supported by Canonical for the life of the LTS.
Things in universe, on the other hand, it depends on community best-effort, there's something like 20k packages in universe, so there's no way of really telling which ones the community will be interested in maintaining and which ones will be ignored. If Lubuntu has said they're not planning on supporting it for 5 years then it's likely they mean those packages as well (though I can't speak for their project).
PCmanFM and openbox are also in universe, so the same thing probably applies. Sorry there isn't a real solid answer, but it's hard to make guarantees on what will be supported when it's based on people's volunteer time.