I believe you meant a hulking death machine with a ballistic six-barreled, self-loading rotary Assault Cannon.
Personally, I want to be able to be a Nob with a Big Choppa, or a snazzy Shoota. Also, screw the Cupcake, I want a good Squig Pie, and I'm sure the Gribblies are tasty no matter how you kill 'em.
For some reason this made me think of Toriko. So I guess there are several steps to this question. The first step is to find the greatest chef in the world and save his life from the tyranids, so that he follows you around and makes you food all the time. Then go on a mission to find the 7 tastiest of the tyranids, so that your follower can make a full course meal. Somewhere along the way, you learn you final form, gather a kill team, and burninate all your enemies with promethium.
Complex interesting campaign system with garrison as important starting point where players are gathering and deciding about their actions. Tyranids random attacks on locations. Large battles. 50vs50 is enough to make me satisfied. Everything above also welcomed. More varied Sm/CSM. Marks of chaos and some chapters buffs. More varied missions where there is something more to do then just running from objective to objective.
Just give me a cyclone missile launcher on top of that and I would be happy plus full Deathwing insignia of course, apart from that I agree with Ostrum's post above...first things first
In the short term, I really just want my damned Looted Boltgun. My looted Asartes Battle Plate would be pretty excellent too.