I'd vote also for a grep text variable. Would be extremely
useful when using an external editor/viewer. Currently this
only works for internal viewer, ie when you open a file for
viewing from the Find results list SS will automatically assign
the find text in viewer so that you can just hit F3 (find next)
to easily locate the place you are looking for.
However, when using an external viewer you have to open
Find dialog and type in the same phrase again and again
for every file in the Find results list. This is driving
me nuts!

On the one hand I want a rich external viewer
with syntax coloring etc but in the other I'm doing a lot
of file greping and have to stay with internal viewer because
of quick text find caps.
One solution would be to customize the external viewer
to extract the the latest grep text from registry:
HCU\Software\Altap\Altap Salamander <V>\Configuration\Grep History\*
Unfortunately it is only updated when closing SS.
So a separate var eg. $(GrepText) would be very useful. This
can be empty string when opening file from the main file
views and the actual grep text when opening file from the
Find results view.