Not critical at all but a "nice-to-have" feature would be the ability to re-group the components that were last un-grouped.

A few times now I've run into fairly complex screens where I needed to ungroup a set of components just so I can modify one component, then go back through the tedious process of selecting all the same components and grouping them again.

It'd be nice if it simply remembered which set of components were in the last 'ungroup' and then just group those back together (sans any components that were deleted of course)

Dan, can you tell me more about your scenario? Why can't you enter the group to edit its contents without un-grouping? Note that group editing was introduced back in August: http://wireframesketcher.com/blog/2011-08-04-group-editing-dashed-and-dotted-line-styles.html

In the most recent case I had a some components I wanted to remove from the group but not remove from the screen i.e. I didn't want to delete them, just make them independent components again so that I could re-position them without changing the bounding rectangle of the group they were currently in.

Dan, I see. However I am not sure a re-group action is the best option here. I find it hard to understand its behavior, especially when some components are removed. Do you know any other graphical software that does this?

How about duplicating the original group and then un-grouping the copy and editing it to your liking? Or you could use copy & paste to copy parts of the group outside of it, then align them with originals and then remove originals from the group. Would it work for you?