My progressed Mercury went retrograde when I was about 15, then, went direct when I was 40. Although my chart is quite afflicted, natally, some things did start to flow much easier in my life when it finally did change direction. I couldn't maintain a daily Taichi practice for years, then, at at the age of 39 in 2007 it flourished and I'm still going now. In 2009, circumstances within an unhappy, long term relationship, that I couldn't find a way out of, suddenly changed, giving me a clear opportunity to leave amicably. I think the best way I can describe it is to say that the river of serendipity is flowing more positively and smoothly in my life, now. But, all that said, while my mercury turned direct in 2008, in 2009, Pluto began to approach my Ascendent, so I think both of these are having a powerful effect on my life and it's difficult to say which one's doing what. I'm only a beginner in astrology, but, from personal experience, I would say, that, having your progessed mercury change direction is something really worth looking forward to. I have to wait until I'm 55 before it comes out of it's shadow, though.
Good luck with it, anyway.