It was the cover that sent fans into a tizzy. Rob and Kristen looking their gorgeous selves in the December 2009 issue of Harper's Bazaar. David Letterman put Rob on the spot about it, and now thanks to @elikarae we know the cover made it on to the Sex and the City sequel:
"R/K Harper's mag in Sex and the City 2...so cute :)"
We got a few more details from @NkHpTwihard:
"There is one scene in SATC2 where Carrie is looking at mail and picks up the New Yorker.. below it is R&K Harper's Bazaar"
There you have it. So enjoy the movie and see if you can spot the mag, I'll be too busy swooning over Mr. Big and Aidan..