Things might get interesting still. If Ferrer wins Paris, he will have around 6000 race points while Nadal has around 6800 points. Ferrer reaching the WTF final would certainly get him close to Nadal, though I must admit I don't know how many points you get from winning a WTF semi. RR matches give 200 points, that much I know.
Hoping for JJ to win tomorrow though, which will render this conversation irrelevant unless Ferrer wins WTF, which isn't likely.
RR matches give 200 points, SF win 400 points, F win 500 points.
If Ferru wins Paris, he needs to make the finals with 2 RR wins to pass Rafa. He'd have 6830 points to Rafa's 6705.
It's a very long shot. Ferru will be dead in London. If he wins Paris, he'll be very satisfied with his season, rightly so, and will be eager for some rest.