Kinda slow in here 'eh?
Allow me to answer my own question in case some other Moto sould wonders the same thing...
I purchased two 2.0 gig MicroSD cards. The first being a Pny card. It did not recognize it. At all. The second I purchased was a 2.0 gig Sandisk, the one with clip art of cell phones on the packaging.
To my surprise and contrary to what the finely educated folks at AT&T AND the Motorola manual states, it does work. I've stored nearly 2.0 gigs of music on the card and as near as I can tell, it's all accessible from the MP3 player.
So there you go.