To get a handle on the amount of data points I’m dealing with, I did some sketching with Processing.  Here are some of the pics.  The main things I realized is that with 535 data points, screen space will be at a premium.  I also have to be careful to use icons that don’t get too muddled en mass or cause weird optical effects (you’ll see some below).  I haven’t played with transparency yet, but I’m sure that will come into play, especially if I end up using some sort of network view, were the data points may end up overlapping on screen.

A few notes.  As you can tell, I’m definitely leaning towards stacked squares as the default visual form.  I tried everything I could think of to make the circles work, but given the number of data points, the circles just will not play, mainly because the space between dots causes a distracting optical effect.  I also like the stacked boxes for creating a a series of vertical histograms, a great way to display multivariate data, especially when much of it is nominal.  However, I’m still hoping to have a “scatter” and “network” mode to allow for some other viewing methods.