Unofficial Halo fan site HaloDestiny.net supposedly got their hands on Halo: Reach's unreleased "Defiant Map Pack" early, and they uploaded some low-quality stills from the three new maps to their site for everyone to enjoy. The site then went down, but the images in question are still available on a separate Flickr account. And here, oh boy!
It will supposedly contain three new maps: "Condemned," "Unearthed," and "Highlands." Condemned takes place on a human frigate, Unearthed has more open spaces, and the main event in Highlands is a giant Covenant ship in the middle of glassing a planet. Since I'm such a n00b, I had to look up the term glassing. According to the Halo Wiki, "glassing" is "a destructive process which signifies an end to a planetary body," a.k.a. a plasma bombardment from space. That's hardcore.
On the Flickr account where the images are hosted, the Highlands map is titled "Training Preserve," so the more-than-passing resemblance it bears to Halo 3's High Grounds may be a coincidence.
How about it, gamers: are you ready for more Reach? Check out most of the screens from the Flickr below, with the rest in the gallery.