Extremely few. I doubt they got enough phones to make any significant difference in the overall numbers.

Totally anecdotally, I reserved a black (sorry, "space gray") phone at Target on Wednesday as a backup plan, in case I failed at the Apple store. They still haven't told me it's ready.

From what I've heard (hooray for rumors!) non-Apple stores are getting just a handful of phones, while Apple's stores are going through hundreds or thousands.