I love the fact that the alignment guides appear when I’m nudging a shape with the keyboard. I’m surprised more applications don’t offer this (yet). Very handy, but I’ve thought of something that could make it better.
I sometimes end up with many objects above or to the left of the shape I’m trying to align, and they’re not necessarily the same size / alignment, so as I move the new shape, I see a new set of alignment guides each time I move it. Would you consider adding some kind of highlighting / hinting to the object that is the origin or anchor of the guide? This would let me know that I’m lining the right things up. (It also presumes I’m warranted in wanting perfect alignment in my rough mockups, but that’s a separate issue.)