It may or may not go away with time but you can't "spot reduce" it away. I don't recommend trying to lose any more weight to get rid of it. How many cals are you eating and what is your exercise routine? Lifting weights and working on core strength exercises might help with it's appearance, pushups, plank variations, etc along with a full body lifting routine like Starting Strengh or New Rules of Lifting.
I would recommend a full body lifting program like New Rules of Lifting for Women, Female Body Breakthrough or Starting Strength. I'm assuming you are a female? Lifting weights will do a lot more for your body shape than yoga or any amount of cardio, especially your core. Forget crunches, sit ups, etc. They really don't do a lot for your abs and are bad for your back over the long term.
Actually New Rules of Lifting for Women does have some swiss ball crunches. His newer books don't use them at all. I usually substitute planks for them, especially since I have back issues. Frankly I have lost 87 lbs and have 4 kids by c-section. I will never have "washboard abs" or wear a bikini. Sometimes that's just life and how we are made! I will say that lifting weights has done the most for improving the appearance of my stomach and overall body shape.
There have been several "loose skin" threads on the Calorie Count Maintenance Board.
Here are a few representative ones.
Congratulations on your weight loss. Time and patience will do wonders.