Connectedconsoles writes:

"It has been rumoured that Halo: Reach could be Natal-enabled when it's released towards the end of the year. And looking at a leaked, in-game screenshot which emerged online today, we think it might just prove that the game utilizes Microsoft's new craze (in the office at least).

First off, look at these two screens below; one from Halo 3, the other from Halo 3: ODST. Notice how the aim of the gun is placed in the centre of the screen in both pictures? And both are clearly firing.

 (Halo 3 image)

 (ODST image)

Now, take a look at the below image. The faint red aim (outlined with a red square) is completely off centre, and a lot further towards the left-hand side of the screen. Well, we think it looks a little like the aim seen in such Wii FPS titles as Dead Space: Extraction and Call of Duty: Modern Warfare Reflex, in which the aim follows the movement of the controller in a view-box.

 (Reach image)

Of course this could be the reaction to a blast, or just lag. But everyone's entitled to their opinion, and this is ours. An AAA title like Halo: Reach using Natal would show just how confidant Microsoft are of it's motion-sensing abilities, allowing tight control of first person shooters."

Source:http://connectedconsoles.com/xbox-Reach-Screen-Proves-Use-of-Natal.cfm 

Click on the first image to see it better.

bungie already stated they dont want natal to damper reach in kotaku and gameinformer

Or it could be an aim button has been triggered. Like in Timesplitters where you can move the cursor all over the place while standing still.

I strongly believe that Natal wont be some sort of interactive war tech where you toss grenades from your couch and run around in Reach aimng with your imaginary rifle etc. It will be arcade like and casual.

I think this is fake. But we'll see.

Its not fake, these pics were posted on Bungie's website. I have no idea what the explanation is though but I'm not going to jump to conclusions. NATAL integration would be a huge investment and everything I've read from Bungie has made it seem that they wouldn't be taking that road.

Look at this vid for reference, the cursor is not dead set and can move about freely without turning the character;

@Mummelmann
It makes sense but I never saw it in a Halo game.

Hisiru; me neither but they did say themselves that Reach will be different in several ways.

@Mummelmann
You killed my hopes for a Natal-Enabled Halo game but I think it's better that way. I still can't imagine how a Natal FPS would work.