Bethesda says that private matches, Deathmatch, and Arcade Mode are finally on their way to Doom. The features will be added before the end of the month as part of "Free Update 3," and ahead of that a “first-look” livestream featuring Marty Stratton and Hugo Martin of id Software will kick off at 11 am PT on September 13. Until then, here's a trailer.
It's short, especially since the last ten seconds is just a reminder of the livestream, but I'll give it this: That is definitely some deathmatch. As for private matches, they're exactly what they sound like, giving players the ability to create their own personal areans, with adjustable settings including time and score limit, and demon and “power weapon” toggle.
How Doom ever launched without a deathmatch mode straight out of the box is beyond me, and Stratton acknowledged at Quakecon that, in hindsight, it probably should have been included. “Given [the player feedback about missing Deathmatch], we’d probably go back and would’ve done it differently and included [Deathmatch],” he said. But better late than never, right? The livestream will also feature a “sneak peek” at Arcade Mode, but that won't be released until later in the autumn.