I/O Window vs Progress (of long running processes)

The current NB convention separates the closing of I/O windows from the 
termination
of the processes running under those I/O Windows.

For example, if you use the Progress UI and Cancel something, or use the 
Stop
button in the I/O Window's action bar the process is terminated but the I/O
window stays around and the user can see the last of the io and things
like "exit satus is 0".
Conversely one can Close an I/O window w/o impacting the underlying process.
The I/O window can be re-opened, not throught the Window menu, but via the
Progress UI.

However, as I've been working on my terminal project,
http://wiki.netbeans.org/TerminalEmulator, I'm a bit hesitant to
follow the above mode. For example, my project will allow the
creation of a TC running a shell. This window may be in it's
own "Terminal" window or in a generic Output Window (I haven't decided yet
what would be best).

Now the purpose of the Progress UI is to track "jobs" like builds
or vcs actions etc. These are long-lasting actions which the use
presumably wants to track, hence the progress UI animation.
But a shell doesn't quite fall into this category. A shell
lasts longer than a build or a vcs action. In fact a "utility"
shell is likely to hang around for the duration of an IDE session.

For such a thing having Progress UI animation seems an unneccessary
distraction, as any animation is.

So, if one agrees that for a long lasting shell job a Progress item
is undesirable the distinction between closing and termination becomes
an issue. Looking at how shells within terminals are used on
the regular desktop we see that a Close of the terminal will
terminate the shell and vice-versa.
This contradicts the current procatice of how the IO window is used.

OTOH, my project will allow the creation of "Command" windows
where one can execute an arbitrary command like 'ls' or 'date'.
For these it _does_ make sense to separate window closing from
process termination based on the current NB convention.

Now, the latest I/O APs from Tomas Holy allow for the creation
of alternative IOProviders and windows. It would make sense, for
example, to have a TC _other_ than Output for shells. However,
the I/O API doesn't allow for the conflation of closing and termination,
which is the sensible thing to do for shells.

The question is then ... should we enhance the I/O API to allow for
the conflationof close and terminate or should shells go into their
own, specialized, not I/O API based TC's?

One way to answer this is to see if there are existing really-long-lasting
actions in NB which are similar to shell as mentioned above for which
the animation of the Progress UI is a distraction.