I may be wrong...but I think Forza 5 says other wise lol
From everything I have read the Xbox One can and does output at native 1080p for some games, but others will be upconverted same as the PS4.
Both will be capped at 60fps max due to the 60Hz refresh TV's limitations. Also keep in mind, the great graphics we are all used to on the PS3
and 360 were not 1080p and still looked great. The main object is FUN and how they PLAY, a good looking game with sucky game play is not a winner.
It also seems if you read a lot of news, that it is "1 single person" a disgruntled reviewer or supposed insider that from what people say can not even properly write a sentence" that started all the "not in 1080p" rumors.
Here are some quotes I found:
"Turn 10 Studios' upcoming Xbox One racer Forza Motorsport 5 will run at 60 frames per second in native 1080p resolution, the studio has confirmed."
"Call of Duty: Ghosts runs at 1080p resolution on Xbox One and PlayStation 4, Infinity Ward has said. That's while retaining the shooter series' trademark super smooth 60 frames per second visuals."
"Despite achieving 1080p at 60fps on next-gen consoles, Rubin insisted Infinity Ward's focus with Ghosts was on the "fun" - not advanced tech features. We've already heard Infinity Ward discuss how the extra processing power of the next-gen consoles has made for improved visuals, but in terms of AI, for example, it looks like the studio is taking a more general approach."
"Update, 4:38PM ET: We’ve spoken with a representative from Microsoft, who provided the following statement: “Xbox One fully supports native 1080p output at 60 fps. It is up to individual developers to determine what resolution best fits their design goals.”
"In general, like with NBA 2K14 most games on the next generation should be capable of natively rendering at the high definition resolution of 1920 x 1080."
"For example the Xbox One 1080p performance at 60 FPS will match the PlayStation 4 with NBA 2K14. But keep in mind some of the initial next generation games are designed to be ported back to the Xbox 360 and PS3, which means some of these games may not push the Xbox One and PS4 hardware as far as the could potentially go. It’s possible that both systems are capable of rendering NBA 2K14 at well over 60 FPS but the renderer is capped at 60 FPS because most HDTVs tend to be 60 Hz."