Whenever this comes up I first think of the scripture that says we will not know the time, and of course I'm a bit skeptical and think how misguided they are. But then I realize they have something right that we generally don't. They're in the perspective that they should be preparing for Christ's return. Albeit I don't believe that the motivation is right, but that's how we should be living our lives. Regardless of the hour we should always live every moment to His glory, and in preparation for His coming.
We should always focus on the great commission as our goal.
I know I'm not the first to come up with this idea, but I think it's still important to bring it to the surface. I also believe that a lifestyle of living as if we are in the last days is completely do-able. If we listen to God's voice and let Him guide our actions instead of expending all our energy running around doing what we believe to be His will.
He moderates our life, giving us the actions to take, and the strength to carry them out. We are also refreshed in Him. His yoke is easy and His burden, light.