Grappling period is, and will always be the most important skill to have in MMA. It will always be easier to close the distance than to maintain it. Unless the rules change, it will never go away.
UFC 1 until now has proven that.
The only reasons people are striking more in MMA is because they are generally trained in BJJ, and wrestling as well, and can negate some of that advantage, so they need better striking because they're on their feet longer. Plus, the rules give fighters more chances on their feet. Without wrestling or BJJ, you're not likely to last long, where a wrestler or a BJJ guy can survive on closing the distance.
Also, in MMA, it's not so much about the wrestling, since relatively little wrestling techniques are used on the ground, and only a few take-downs are used on the feet, but about an already accomplished set of athletes (wrestlers) being taught the martial arts. There's a larger pool of them for an American based company, they're used to cutting weight, hard training, and they already have a ground base that they can launch from.
Since MMA figthers now have access to high level coaches in striking, BJJ, and wrestling, it's now more about the athlete.