Some additional details from Matt Jolley about editor wish-list items:

1. Change island in 1 or a few slices (as opposed to fully connected). I often end up touching up complicated surfaces by hand and the inability to restrict the current option (it only does 3D) leaves me touching things up with simple paint which is not as precise or as true to the original surface. If I utilized the "unrestricted 3D" tool it often leaks out.

2. Remove island. Remove areas less than X pixels of within another region. The current one does not seem to work like the old one. There is a series of filters in Seg3D that helps me with this, but it is not the same. Ability to do in a single slice, a few slices, and globally.

3. Remove fluff(groups of pixels less than X). There was never a tool for this, but it would be nice. It is pretty simple and I figured out how to do it in Seg 3D. First, run the connected component size filter (in Mask Filter menu). This creates an image layer that separates the islands by size with the size of the volume corresponding to its data value. then run a threshold filter on the image using the size range histogram you want to retain as the threshold values. This allows rapid "cleanup" of messy segmentations with a few pixels here and there after other operations. So no need for this now for me, but a simple tool rather than multiple operations in seg3D would be easy to implement as it is all in ITK I think.

I believe the new Segment Editor support the concept of scope.

Copied from http://wiki.slicer.org/slicerWiki/index.php/Documentation/Nightly/Modules/SegmentEditor

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Masking: These options allow you to define the editable areas and whether or not certain segments can be overwritten.

Editable area: Changes will only appear within the selected area. Options include: Inside All Segments, Inside All Visible Segments, Outside All Segments, Outside All Visible, Everywhere
Editable intensity range: Only areas within the selected intensity range will show changes that are made to the segmentation
Overwrite other segments: Select which segments will be overwritten rather than overlapped. Options include: All segments, Visible Segments and None

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