It would be nice if we could see which apps will be for the RT before we ordered the machine. I have ordered mine and have no idea what apps will be available, something seems wrong with this picture.
There isn't a specific section, at the moment anyway, but from any windows 8 machine if you browse to an app in the store it will tell you supported architectures. If it says x86, x64, ARM - it will work on RT. if it only says x86, x64 then no RT.