According to The Vampire Diaries EP Julie Plec, Elena’s human death will have a heavy impact on Matt and Jeremy when season 4 begins. Their plotting and actions had serious repercussions to Elena’s now uncertain future and will most certainly trigger not only guilt, but reaction and possibly retribution.
“I think that’s the worst tragedy of all is that they plotted together to get her out of town so she wouldn’t have to be part of this life. And now as a result of having been on that bridge at that moment, Matt is basically responsible in his own way for her being the one thing she never wanted to be. He’s going to carry that very heavily. It’s going to take his some time to get past that. And I would say certainly Jeremy, who would never want this for his sister, is going to have a real, real visceral reaction against Rebekah for what [she] did. There might be a little bit of retribution.”
Source: TV Line