Well, I heard that there have been plans for them to continue the story but have never gotten far. This is what I've heard and also what I think should happen;
Trunks has freed the future and now the world is healing and being rebuilt. Trunks is still not satisfied because it took so long to defeat 17 & 18 and so many people still died from them and even those from the imperfect Cell. Trunks even returns to what's left of Dr. Gero's lab and finds 16 still in his capsule. Bulma reprograms him to be on their side. Trunks knows that the if they could find the new planet Namek, they can reverse what's happened but they have no idea where that new planet is. So Trunks goes to the lookout and asks Mr. Popo to take him to the next world. Mr. Popo is able to convince King Yama to let Trunks see King Kai, even though he is not dead. Trunks heads down Snake Way and at his power level, it doesn't take him long to make the trip. King Kai finds the location of the new Planet Namek and gives Trunks the location and tells Trunks that they'll be in touch. Trunks returns home and tells Bulma the location. He, Bulma and 16 prepare the spaceship, just like the one that Goku used and head off.
During the travel in space, Trunks meets a strange being who shows him what his world would have been like if not for the androids. He sees himself sitting outside in the garden of Capsule Corp at the breakfast table with his mom, his dad and even his little sister, Bra! He finds out that he would've been best friends with a boy known as Goten. It's painful to Trunks to see what he could've had but the being says that perhaps he still can have it. While still traveling, they run into those people in that mirror coated ship, again. The kids are now adults and they recognize Bulma and Bulma introduces them to her son, Trunks. Trunks is wearing his saiyan combat armor, just like Vegeta's and tells them not to let it scare them. They explain to Bulma and Trunks that they made it to the new planet they were searching for and even heard about Freeza's defeat by the saiyan known as Goku and thought the universe was safe but they soon learned that it wasn't. It turns out Freeza had an older brother, Cooler and when Freeza died, Cooler took over the entire empire and is even stronger than Freeza. Cooler brought the army to their new planet and but they retreated in their invisible ship. When they wouldn't reveal themselves, Cooler destroyed their new planet as he didn't have any use for it and so now they've been living in space in the ship ever since. Trunks is mad at this. No. 16 can't understand how someone would want to destroy life. The people decide to join Trunks and Bulma in their quest for the new planet Namek.
When they reach the new planet Namek, Trunks quickly senses a huge power level. He also finds warriors that are dressed in combat armor. Trunks, 16 and the others make quick work of them. Trunks eventually finds out that Cooler is the one on Namek and he too wants the dragonballs to wish for immortality. The Nameks tell Cooler that he won't get his wish even if he collects all 7 of the dragon balls but Cooler replies to that in the Namek language which surprises them. He reveals to them that he's aware that the dragon has to be summoned and that the wish has to be asked all in their native language and he knows enough of their native language to get by. The Nameks are greatly worried. Cooler tells his men that they may do as they wish with the Nameks but he wants Mory the eldest, alive and unharmed...at least until he gets his wish because if Mory dies, the dragonballs are useless. Trunks goes after Cooler and his men. No. 16 helps as well and so do the people in the invisible ship. During the fight however, the invisible ship is destroyed and they wonder how they'll be able to leave the planet. Cooler fights Trunks and then uses his 4th transformation for battle and he proves to be quite a tough opponent for Trunks. Trunks does not give up and is able to defeat Cooler.
With Cooler defeated, they can now use the dragonballs to repair everything that was done on Earth. Trunks says that they have to wish Piccolo back first so that Kami will return and so will the dragonballs, but Mory tells Trunks that since their encounter with Freeza, he's given the dragonballs a little upgrade, so now Porunga has no limit to how many people he can revive. Trunks says that's perfect! Dende does the honors. They use the first wish to restore all the Nameks back to life. They then use the second wish to restore everyone that the androids and Cell killed, excluding Dr. Gero. King Kai tells Trunks that he can sense the energy increase and says that everyone killed on Earth is back! Trunks asked that even his father, Vegeta and Gohan are back?! King Kai says yes. There is still one wish remaining. Trunks decides to take a chance and asks Dende if they can wish Goku back to life? Dende makes the wish but Porunga says that he can't grant it because Goku's death was natural. Trunks says that they tried. Bulma does have a wish. She knows that Vegeta is alive again but it's been so many years and she wants to give her relationship with him another try so she asks Dende to have Porunga make her 25 years younger. Porunga does so.
Trunks, 16 and Bulma invite Dende to come back to Earth with them because they'll need a new guardian soon for Earth to keep the dragonballs going. They also invite their friends from the invisible ship to come live with them on Earth and they accept. One of the females has developed a romance with Trunks. So they head back to Earth using Cooler's spaceship.
Meanwhile on Earth, everyone is amazed that they're all back alive. Gohan hurries home and Chichi is overwhelmed that he's alive again! Vegeta can't believe he's alive, too. All the fighters can't believe they're alive. Soon they sense an energy approaching Earth and see that it's a spaceship, just like the one Freeza had! When it lands, they're prepared to fight but when it opens, Trunks steps out and Gohan recognizes him and tells them not to attack. Gohan and Trunks hug and Trunks tells him that he beat the androids and Gohan says that he knew Trunks could do it. Gohan sees Dende and they recognize each other. Trunks then sees his dad and Vegeta can't believe that his son is all grown up and even a super saiyan. The Z fighters are all impressed at all the things Trunks has done and Gohan believes that Trunks should be the leader from now on. Trunks says he'd be happy to lead as long as they're all with him. They all agree but notice that Vegeta is keeping his distance. Vegeta says that he's not really a people person but if they ever need him to help out because THEY WILL, he says he'll be there. A year later, everyone is celebrating the world now being completely rebuilt and freed. Bulma and Vegeta have started over and have even had a daughter, together, Bra. Trunks is now in a relationship with the girl he met from the invisible ship. Gohan has returned to becoming a scholar and apparently has found his way to Videl. The leader of the royal military gives Trunks a great commendation for his services to the Earth. At the end, everyone is standing in front of Goku's grave paying their respects.
That's some of what I've heard and the rest is what I think should happen.