I would be insulted and disappointed by this news if I was a Saints Fan, That disappointment wouldn't change whether they do or don't sign him. Just bringing him in for a workout tells me that the Saints organization would sign him despite his past, but will only sign him if he is in shape and the NFL gives them the answer of "he can play this year." I highly doubt this is a move about next season.
Saints are basically sending the message of "we don't care what this POS has done, its all about winning."
I heard one reporter say something to the effect "The Saints in the back of their minds are probably thinking about fan reaction, but don't really care long term, especially if they win a SB."
Just shakes my head at this mentality.