Guys, no maps are leaked anymore. They have overviews on Bungie.net now, of all Halo Reach Multiplayer and Firefight maps. Just look in Global Heatmaps.
SUPER THREAD UPDATE! Added all heatmaps and an image for glacier. If anyone has images of boardwalk, countdown or glacier please PM me or post it in a reply.
The length does give it a very Narrows look, but honestly its asymmetry is the most important factor in setting it apart from those two maps. I'd say that High Ground with a dollop of Narrows back and forth would be a better description, personally.
YouTube - Halo: Reach - Quick Look Boardwalk I psyched for Boardwalk, personally. Oh, and Headhunter EDIT: Countdown looks sick too, they had a SWAT gameplay video on it.