I'm not into Halo 2 as much as I used to be, but I've had my eye on the new Relic map since I heard about it and saw glimpses of it.  There's a new article on it over at Bungie.net that describes it in detail.  Like Zanzibar, Relic looks and feels like no other map.  I think that's because of its asymmetry and its “natural” appearance and environment.  Teams will have to put a lot of brain power into CTF and assault, and the map has many unique features that will keep things interesting.  The article does a good job of explaining the map along with some strategic details.

There's also a video that highlights some gameplay and a few of the neat features of the map (available on a halo.bungie.org video page: http://nikon.bungie.org/misc/maptacularvids.html).  The video page also has videos of some of the other newer maps. 

While I'm eager to see and play the new map, I'm skeptical I'll actually enjoy it as much as I hope.  I just don't meet up with friends online or in person to play Halo 2 as much as I used to.