Heres the main link to this rumor:
http://halo3blogs.com/2010/08/21/gamescom-halo-reach-forge-wo rld-map/

Heres an important part of this blog:
He then told everyone that another Forge World map will be revealed.  Other attendees also explained that this map will have different climate than other areas of Forge world

My main speculation would be that this going to be forge world but with snow on it, Same map do. 
 
We will see today at GAMESCOM what they were reffering to.  As for now we have VERY solid info that there will be a new climate on forgeworld!:D

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Stay tuned!


<<<<<DISCUSS>>>>>    

That would be even more amazing :| I still cannot believe how much they're putting into this game.

L O L  what a bullshit rumor. Full game leaked already and there's only one Forge World

Ah yes, just read the full article " According to a story from a Gamescom attendee", aha!
 
" Folks at Gamescom explained that after the camera, video taping the Halo Reach Campaign, turned off, Brian Jarrard continued to play Halo Reach and speak to the audience. "
 
Hmmmm, pretty convenient, I'm sure he would've revealed it whilst the cameras were still on as it's a pretty big announcement to make.

I don't buy this rumor.

" L O L  what a bullshit rumor. Full game leaked already and there's only one Forge World "

" @Lies said:

" L O L  what a bullshit rumor. Full game leaked already and there's only one Forge World "

Wait, the game has already leaked? WTF! "