What, you say? Because haven't we been being told by the show's creator herself that Meredith and Derek are going to remain together and happy this season?
Well, courtesy of EW's Michael Ausiello, there's already an explanation:
"That little promo caused quote the little firestorm over at ABC yesterday. Not only did it incur the wrath of millions of Rose-weary Mer-Der fans, but it essentially branded one of the network's most valuable assets (i.e. Shonda Rhimes) a big ol' liar. You see, in her ABC podcast that followed the show's finale last May, Rhimes assured fans that Grey's would not be employing any soap operatic stunts to pull Derek and Meredith apart this season -- and she specifically ruled out knocking up Rose. But someone apparently forgot to pass that bit of information on to the folks cutting together that incendiary clip. As a result, Rhimes has been forced to do the unthinkable: Issue an exclusive statement to me that basically denies the very plot twist that ABC shamelessly tried to dangle before us. "I would not deceive our fans," Rhimes tells me, "especially those loyal enough to listen to our podcast." Long story short: The only thing Rose will be carrying in the season premiere is a third wheel."
All together now: Phew.