I don't think anyone is foolish enough to sign him as a starting QB. But, I could see someone giving him a contract to come in as a backup with a chance to compete for a starting role. Personally, I like him in the Joker role.
And, I'm not convinced that the Saints see Jameis as a significantly better option. If Jameis light it up against the Niners, do the Saints still put in a lesser QB and risk losing just because CSP made a promise to Taysom? I'm not buying that.