"As it is" is a reference to the current state of something, and how that needs to accounted for. It is synonymous with "because of the way things are".
eg As it is we cannot take this road, but have to take that one instead.
"As such" is a phrase used to confirm that something is meant in an exact and literal sense. It is synonymous with the word literally.
eg There isn't a bathroom, as such, in this cheap hotel room but there is a room with a toilet!
As such is also a little antiquated, and typically only used when trying to sound very formal. "As it is" is used far more commonly.