The problem the D'677 patent faces here is that the USPTO has determined (for **w) that this patent "is **t entitled to benefit of the filing date" of two previous Apple Design patent applications because the Design at issue was **t disclosed in those earlier applications. As a result, certain prior art is eligible **w, and against the background of that additional prior art, the USPTO believes the patent shouldn't have been granted.
Apple was originally awarded over $1 billion from the original lawsuit, but that amount has been reduced substantially to about $548 million in damages. Aside from this particular Design patent, Apple still has other claims that have **t been reduced or invalidated from the previous decision.
Samsung was most recently denied their latest appeal attempt, leaving them with the only option of turning to the U.S. Supreme Court. It appears this invalidation has ** direct impact on the current standing of the lawsuit, but may help Samsung in their appeal to the Supreme Court.