Ah, this is what those so-called Grockets were about. Valve has collaborated with WETA Workshop's Greg Broadmore on Dr. Grordbort's Victory Pack for Team Fortress 2. I rarely play as the Soldier, but space guns and mutton chops are quite the compelling argument.
The pack introduces two weapons -- The Cow Mangler 5000 and The Righteous Bison -- both of which are seriously anti-Engineer. Plus, hats: Lord Cockswain's Pith Helmet and the aforementioned mutton chops (which also come bundled with a pipe. Rad.)
The items can be obtained by way of loot drops, crafting, and the Mann Co. Store. There's also a brief comic for the obligatory backstory.