I think there will be a long road from SL to training camp for many of the young player.
there will very likely happen some more moves from the FO after the SL that will change a lot.
the signing of Haislip definitely has reduced the chances for Gist, no matter what position he can cover. if he can't be a full time 3, his chances are almost non existing. if he somehow makes the transition, he still isn't a safe bet. (without Haislip the athleticism from Gist would have been his best asset and also the option to find minutes at both forward spots)
don't forget, he already is in Europe and has earned some reputation there. it's easier to find a good fit for him there (for decent money), than it would be for McClinton, Hairston (who's right Spurs don't own anyhow) or Williams. if the Spurs wanted to keep either Hairston and Gist, but don't have enough spots, it is smarter to chose Hairston this time. (ok, I was wrong about this last season either).
and finally: Gist's rights might have some value as a teaser in a trade, especially if he plays a good SL. some rebuilding teams might be interested in a cheap future option. (Clippers, Sixers and Pacers would have room for another athletic combo forward. also the Grizzlies, if they don't keep Warrick)
if McClinton impresses in the SL (and is as good a defender as Pop announced) and maybe even shows some playmaking ability, he should be a lock, considering what type of player Pop obviously was seeking in the last season. (Stoudemire, Pargo) this might even make Hill expendable, who also has some trade value).
I think McClinton might become the biggest story of the SL. (from a Spurs perspective)
it's always pointed out that he isn't a playmaker. but he is a pretty good ball handler and passing and decision making is something a player can learn to some degree. he is really tough and seems to stay cool in moments when Hill struggled. I'm sure he will put a lot of pressure on Hill.
and then there is Ian. right now he is in a position without many options. he can't be sent to D league next season, so if he doesn't at least play decent in this summer, I see him go the Beno route. Spurs will pay some or even all of his salary to get him out of town for a TE. (there are plenty of such TEs out there that would fit). that's still 1 million $ less expensive than have him rot on the bench without the option to play him in Austin. it would also clear a roster spot.
I have never been high on Ian (I'm not happy if I was right) and I truly think this is the most likely scenario. (again, I won't complain if it isn't).
btw. what if Rasho is willing to sign for the veteran minimum? do we rather have Rasho on the roster or Ian? (for more or less the same price). or Mihm, or Magloire, just to drop some names. if the Spurs are confident that Tiago will come in next summer, there is even less reason to keep him.
so I think from this SL roster Blair is a lock, McClinton has a very good chance and then it will be between Hairston and Williams (likely not decided before end of pre season). Gist will go back to Europe and Ian will be gone.