On replay, sliding really was not an option. He was diving/falling forward because the Safety got a piece of him below the knee.
But, if you watch the play from the snap, the best option for Wentz on that play was to throw the ball away as he had the safety in front of him to contain him from getting outside, thus forcing Wentz back inside where the help would come from. Plus Wentz was several yards behind the LOS behind he tucked the ball away to run so there is no benefit of taking a hit on that play, as he wasn't going to gain many yards (think that play ended in a sack because he didn't get back to the LOS). QBs should run and absorb contact only if it's 3rd down and they are fighting for the 1st down. Otherwise, slide early and trust in your abilities to make a throw to secure the extra yardage that sliding early prevented you from getting on the next play.
That's the main takeaway for Wentz and the Eagles moving forward. They need him on the field. Guys like Jackson, Allen, Murray, etc. like Wentz, RG3, Newton, and Luck will use their athleticism to run, but it takes a serious injury before the team will have second thoughts about continuing to do it. You can run and use your mobility, just need to be smart about it. Understand the Risk/Reward. Extra yardage isn't worth taking a hit unless it is 3rd down and you have a shot at making the first down.