My guess why this trade hasn't happened yet:
San Antonio wants to see if the player they want is available at 7. I'm guessing that it's a player Toronto would likely pick which is why SA is in discussions with them. However, Toronto isn't going to take on Jefferson's contract like the Kings will. Would Toronto want Valanciunas? If so, that's got to be who SA wants and it might just happen that he drops to 7 considering his buyout won't make him available for at least a year. (Duncan is aging and they've done the draft and wait thing successfully before with Robinson). That buyout news is pretty recent as well, which would explain why this trade rumor came about just now.
My guess why we know about this trade discussion:
The Kings want to increase the value of the 7th pick and someone leaked it on purpose. The Kings will start getting other offers from other teams and apparently have a lot of interest already. That's why the Spurs are saying that the trade is a longshot. They want to decrease the value of the 7th pick. We came close to getting Deron Williams last season and it would hurt to miss out again. But this is why it's good to have Geoff Petrie in charge and not someone like David Khan. What Khan is doing with the 2nd pick is embarrassing because he's basically admitting the 2nd pick has no value to him. Petrie on the other hand worked out a lot of players and has everyone certain that he likes multiple players at 7 even though that might not be the case.
San Antonio wants to see if the player they want is available at 7. I'm guessing that it's a player Toronto would likely pick which is why SA is in discussions with them. However, Toronto isn't going to take on Jefferson's contract like the Kings will. Would Toronto want Valanciunas? If so, that's got to be who SA wants and it might just happen that he drops to 7 considering his buyout won't make him available for at least a year. (Duncan is aging and they've done the draft and wait thing successfully before with Robinson). That buyout news is pretty recent as well, which would explain why this trade rumor came about just now.
My guess why we know about this trade discussion:
The Kings want to increase the value of the 7th pick and someone leaked it on purpose. The Kings will start getting other offers from other teams and apparently have a lot of interest already. That's why the Spurs are saying that the trade is a longshot. They want to decrease the value of the 7th pick. We came close to getting Deron Williams last season and it would hurt to miss out again. But this is why it's good to have Geoff Petrie in charge and not someone like David Khan. What Khan is doing with the 2nd pick is embarrassing because he's basically admitting the 2nd pick has no value to him. Petrie on the other hand worked out a lot of players and has everyone certain that he likes multiple players at 7 even though that might not be the case.
Interesting speculation on Valanciunas. That's definitely plausible.