I was thinking about this the other day and I dont think its gone do much for either guy. If Tito were to win, it will look alot more impressive than if Jones was to win. But Jones has fallen soo much in recent years that a win over him is in the same calibar as for example Berbicks win over Ali. Its not that significant.
It doesn't count for much now, but probably will in the years to come as people forget how declined these guys were. It also depends on the fight - if it is a competitive, back and forth war, I think it probably counts for more than if it's a one-sided blowout. I also think it might count for a bit more if Trinidad pulls off the upset - as he's coming off two years of inactivity, is the smaller fighter, is expected to lose and so on. If Jones wins, it basically allows him to stay in the game and get that big money rematch with Hopkins or fight with Calzaghe.
To me this is an exhibition type fight... a fantasy matchup between two guys that are obviously differant sizes... and at the end of their careers. A win or lose doesnt do much eather way imo...