You can have as many weapons as you want.

Thank you! This is one thing I've been waiting to see from an FPS game made by someone other than Id and Raven for the past few years. Too many games that have been like "Oh, it's tactical realism, so you can only carry two, and no, you can't have a pistol sidearm; that'll eat up one of the two slots", or "You can only carry X number of inventory units before you have to drop something". Save that stuff for the RTS/RPG nerds; let me explore the world, then retune the skill levels and explore it again.

That's why I loved Wolfenstein (2009) so much: you could carry all the weapons you wanted, and there was no shortage of ammo, and it was fairly obvious where to find ammo. I'm playing through Fallout 3 again, and getting angry at how the Sniper Rifle basically sucks because it turns to powder after 50 shots, you can barely find any .308 ammo unless you explore all over the place in secret stashes, and so on. I know, "it's supposed to be difficult; it's Fallout! Nobody cares about your silly fantasies of fun romp-around games where ammo can be easy to find and you can have 9000 pounds of weapons on your back at any time!" I'm glad that Id is focusing on fun and exploration; they probably won't skimp on challenge in the higher skill levels.