If you are serious about landscape photography, I'd suggest you go all the way on tripod and head. A good tripod combined with a good ballhead can last you years and is a worthy investment. (At least it's more of a sure bet than on the volatile and unpredictable camera market).
If you can afford it, a Gitzo tripod and either Arcaswiss or RRS ballhead.
Since there's so much in doubt over the camera release schedule and supply, I'd suggest just keep using ur XT and lens for the time being. Having the gear to take photos is the first priority; with that taken care of, I think waiting would give you more time to factor in new announcements, plan ur strategy (whether u really want to go FF, and if so, sell ur gears and replace them with EF lenses), and save up.