Ellen Pompeo
Actress Ellen Pompeo, of the series "Grey's Anatomy," arrives at the 2013 People's Choice Awards in Los Angeles, January 9, 2013.Reuters

Season 12 of "Grey's Anatomy" is still months away, and it's still a mystery how the show will move forward now that one of its main characters, Derek Shepherd, is dead.

The actor playing Derek, Patrick Dempsey, exited the show before its season finale, and now speculations are rife that the show is going to focus on Ellen Pompeo's Meredith Grey. Rumours are also rife that Meredith's Alzheimer's storyline will be the highlight of the upcoming season. Fans have also been wondering if Meredith will learn to forget Derek due to her illness

Elsewhere in the season, we will see April and Jackson finally taking a decision regarding their relationship. April and Jackson have not broken up yet, but their relationship has come under a lot of strain ever since April went off to serve the army.

Meanwhile, Arizona and Callie will reach a good place in their relationship where they will learn to co-exist without any hard feelings. Jessica Capshaw told TVLine recently that big things are about to happen for Arizona in season 12

As for Dempsey's exit from the show, there are conflicting reports on why the actor decided to leave when he was at his peak. But someone who understands what Dempsey was going through is Jeffrey Dean Morgan, who played Denny Duquette, one of the most memorable characters on the show.

"I guess it's run its course for some of those people [who] have been there for 10 years, and at a certain point you don't want to do that character anymore and it's time for new challenges," Morgan told HuffPost Live.

"And I get it. I get [Dempsey] being ready to say goodbye and I get the show being ready to move forward and introduce some new storylines. Look, 10 years is a long time. I don't think I could last in anything for 10 years doing a character," the actor added.

"Grey's Anatomy" will return to ABC this fall.