Many on display next to the Watch display , only the lower configuration . It will be my next laptop without a doubt . Tried it and found it to be very responsive and extremely cool. They did not have it available . Will buy it at Best Buy , when available.
Can confirm that Towson, MD has them on display. I failed to ask them about purchasing one at the store today.
They also have the Apple Watch for try-ons (duh). Fortunately, there was no wait, and they took me early for a try-on (I had a 12:45 appointment and they took me at 11:45).
If you're in the greater Seattle area, the Apple Store at Bellevue Square Mall in Bellevue, WA has all three (gold, space gray, silver) Retina MacBooks available to try.
Fun fact: Microsoft is the largest employer in Bellevue.