On Wed, 12 Dec 2012 10:15:44 -0500, Greg Guarino
So there's my next question. My only option for making dadoes is a
router, and I'd love to avoid making extra passes. If I buy a 23/32 bit,
will I be OK? Or is plywood thickness too unpredictable these days?

Plywood thickness is *EXTREMELY* unpredictable these days and has been
for a number of years. You might get lucky and be able to find a
router bit perfectly sized for the plywood on hand, but the chances of
that happening are almost nil.

Sorry, but multiple router passes are usually the norm if you want
your dados sized properly.

On thing you might consider, is an adjustable dado blade for the table
saw. Get that sized properly and *then* you can do your single passes.