According to this eWeek article pay premiums for skills that don’t have a certification grew three times faster than pay premiums for certified skills.
I never really bothered with certifications for any of my skills because I was usually too busy working to set aside the time to study for and pass the exams. I was more motivated to do that for things like grad school. I always felt that experience was more valuable than a certification, but the counter-argument of “if you have the experience, certification should be no problem” is still a reasonable one.
Still, I hope the pay premium changes mean employers are choosing experience in favor of those who’ve passed an exam but have little or no hands-on experience.