What should happen if the selection consists of multiple parts and/or
non-rectangular or otherwise irregular shapes?

Is it possible to select area for cropping other than rectangular?

OK - let's precise it like this:

enhancement - when selecting rectangular area and especially - when cropping -
the center of the selected area to be visible

Well, you're using PS as an example - how does this app handle the center for
selections that consist of multiple parts?

Currently, cropping is limited to rectangles, but cropping to ellipses has been
suggested, and there is not reason why one shouldn't be able to crop to a
triangle or another polygon.

Well, since layers and images are rectangular, I'm not sure what it would mean
to crop to anything other than a rectangle.

sas, the new version of the crop tool under development will show you the
coordinates of the center of the rectangle, and will allow you to set fixed
values for them.  Is that enough, or do you actually need a visible mark at the
center?

Well, I need to have the centrer exactly in the middle between two 'elements' -
both in vertical and horizontal direction - so I suppose that if it is visible
it will be much easier.

Thanks for the replies!

I can imagine that a visible mark helps when cropping. Perhaps the crop tool
should draw diagonal even. What I can not imagine is that someone would want to
enter the coordinates of the center manually or even see a label that displays
them. What is the point of having that functionality in the new crop tool?

That should have read "Perhaps the cropt tool should draw diagonal lines,
crossing at the center, even ..."

The crop tool in cvs does have the ability to show center lines (also thirds and golden mean). Vertical and horizontal lines only, though. 

But we should at least confirm this report now and decide whether it is considered fixed or if diagonal lines (comment #6) have additional advantages.

Closing as FIXED then.