he s just jabbing high to work the shoulder more. the thing he does is he telegraphs real bad- you ll notice he shakes his right slightly before he jabs it. floyd is a master and reading punchers who telegraph. thats the main problem, not his speed. its a bad habit lots of guys have, hatton for example, juked before he hooked.
I think the high-jabbing might be some sort of distraction to set up the left through Mayweather's philly shell guard. I don't think it will do much for him, but if Floyd starts looking for a shot up top, it could work as a blinder to set up other things, I guess.
To regain his green belt? Floyd has gone on record as holding the WBC in highest regard, almost to the exclusion of caring about any other titles.