The Exo-45 Patriot Exosuit is a walking tank with what appears to be both a missile platform and a chaingun, likely capable of punching toe-to-toe with the Automaton's biggest heavies. Players have been hungry for more armour-piercing options (especially after the horrors of Malevelon Creek) since the game's launch, to supplement the existing Autocannon and the all-powerful Railgun.
It'll be interesting to see how strong this thing actually is on the battlefield, though. While it's easy to think becoming a walking turret would even the playing field a bit, I should mention that I've only survived most of my higher-level missions by being a devilish little scamp and manoeuvring cleverly.
Depending on the actual HP of these mechs, clambering into one might be a death trap—easily countered by an Automaton tank shell or two. Despite armour-piercing being the main draw, these things may be more effective against bugs as part of a manned defence, with mortars and other players playing 'protect the president' on the battlefield.
It's unclear whether mechs will be released with the other leaked vehicle options spotted on social media, but they all seemed to be in roughly the same state when they dropped into unwitting players' games so it seems at least a possibility. Arrowhead has been keeping relatively tight-lipped on whether these items are spawning at the hands of rogue datamining Helldivers, or are sneaky blessings from the one-and-only Joel.
As for when it's coming? Apart from "soon", Arrowhead Games didn't give us a date, unfortunately—but that's unpatriotic talk anyway. Our patriots on Tien Kwan are working as hard as they possibly can, and you didn't sign up to ask questions, soldier—report to your nearest Democracy Officer.