Arya's new dragonglass weapon that she asked Gendry to make has been revealed in Game of Thrones season 8, episode 2. Last week's episode, the Game of Thrones season 8 premiere, "Winterfell", brought several characters together for the first time in many years - both in-universe and in real time. One of those pairings was Arya and Gendry, who left King's Landing with each other several years before and haven't seen each other since Gendry joined the Brotherhood Without Banners.
Of course, with Gendry joining Ser Davos (and later Jon Snow), and Arya returning to Winterfell once she heard her family had taken the castle back, both Arya and Gendry are now preparing for the ultimate fight against the Night King and the Army of the Dead, which will come in the Battle of Winterfell - the subject of next week's episode of Game of Thrones. So, to prepare for the forthcoming battle, Arya asked Gendry to make her a weapon. At first, it was widely believed that it was a projectile-type weapon, but it appears that's not the case.
As revealed in Game of Thrones season 8, episode 2, Arya had Gendry make her a double-edged spear, with the edges made entirely out of dragonglass. This would allow Arya to fight multiple wights (or White Walkers) at the same time. It's unfortunate that her trusty ally, Needle, won't be of much help in this fight, but one thing is certainly clear: Arya can turn practically anything into a weapon at this point. Having a double-edged, dragonglass-based spear is just something that will be more useful, is all.
Interestingly, earlier in the episode, Arya visited Gendry and asked him if he'd made her weapon yet. He didn't. But once he saw Arya demonstrate her capacity to kill by throwing three dragonglass-based spearheads at a wooden post, he started making her weapon straight away. Audiences will just have to wait and see if Arya's new season 8 weapon will come in handy when she takes on the Army of the Dead in the Battle of Winterfell.
Plus, this heavily resembles the staff that she learned to defend herself when she was blind and training to become a Faceless Woman. Given the fact that she will be fighting at night, and during winter nonetheless, Arya is perhaps more comfortable using the new weapon Gendry made her than she is using a sword like Needle. It's all about precision and being about to take out multiple enemies at once.
Game of Thrones season 8 airs Sundays at 9 pm ET on HBO.