Got mine today! Looks like I was worried over nothing when I didn't get the confirmation e-mail even though I knew I was one of the first (maybe 7th?) to order. I eventually got two shipping confirmation e-mails yesterday or the day before, though. Weird. But that matters not any more.
Haven't played it yet. Everything is very high quality, especially the cart and the manual. The box art is a bit odd without the full "Genesis" and "Mega Drive" names. If it ends up bugging me over the long term, I'll use DJ Shock's artwork (which I have downloaded). There is a bit of ink smearing on the back in the text.