There's at least one report of calling Apple Friday morning and being told the dates are "to manage expectations" and some 4-6 weekers would likely receive theirs earlier.
Was near an Apple store today so walked in. Surprisingly, not only did they have the display table and reservations area, but this small store also had three models on the floor for demoing - that no one seemed to notice so you could walk right up to. Confirmed 38mm was best for me, but I wonder what those extra pixels would do (on maps, etc.)? 42mm didn't look as huge as I feared (and VR examples showed). Still experience with the chunky LG G has me more nervous of too large, than too small.
Same here on the black sport. Suspect they sold a high percentage of those.