There's been a variant of Blood Gultch in every Halo game, I cant imagine there wont be one in Reach. There will probably also be a variant of Zanzibar/Last Resort too, since it still stands as Bungie's finest map-making moment.
But if you're hoping that the map will be as simple and one-dimensional as Blood Gultch, then you might be disappointed, because based on the level of detail we've seen in the maps thus far, chances are the new map will have even more nuances and terrain variability than Valhalla.
Personally, Im more thrilled about a spiritual successor to High Ground (Overlook) than I am about another symmetrical two-base map.