I guess it's possible that Portland and SA could do a S&T of both Joel and Nazr. Portland would still need a C and they could still try to trade Zach Randolph (I read they were looking to do so). This way both teams are still able to use their MLE for someone else. However, the key would be to get Nazr to agree to it. I guess if you offered him a little more than the MLE he might take it. It's long shot, but if the Spurs could pull this off then they could still pursue Jared Jeffries or someone else (Speedy).
If the Spurs could pull this S&T then they could threaten to sign Speedy outright. The Hornets might blink and agree to take Barry in exchange. Then the Spurs could turn around and offer the full MLE to Jeffries. Hey, it's possible.