In my view and experience, as long as Mercury is moving slowly as it does just before and just after the retrograde turn its effect on communication and frustrating events remains strong.  As Mercury begins to pick up speed there is more of an ease of motion that helps to lubricate both verbal communication and the transmission of energy in general.

The sign that Mercury is in and the aspects that it makes to other planets have a great deal to do with the effect of the retrograde period.  Mercury is in Sagittarius now where it tends to instill a broader vision that can be particularly frustrated by the retrograde, and the fact that Jupiter and Uranus are approaching their final conjunction in Pisces is creating surprising changes and turns of events.  This conjunction of Jupiter to Uranus breaks apart our preconceptions and requires that we release the past in order to move forward into a new breakthrough of awareness and experience.

Mercury will not begin to pick up speed until after the Capricorn New Moon on January 4th.  A New Moon in Capricorn, the sign of achievement, is a wonderful time to set intentions for success in business or other practical matters.   At that time Mercury will be in range of a challenging square to Jupiter and Uranus which may make it difficult to concentrate, but it could also encouraging the breaking free (Jupiter/Uranus) from our own inner blockages so that we can create a new reality in their place.