Although the specific link between the 1976 H1N1 vaccine and GBS remains unknown today, a blog posting from 2009 indicates that possible triggers for GBS do include infections and their vaccinations in rare cases. That same blog also eases some worry for the recent fear of an H1N1 outbreak, and is further supported by the CDC's preliminary findings on the issue published the following year.
The general consensus is that vaccinations can, in especially rare cases, lead to the onset of GBS. While 1976 did indeed have a significantly higher number of cases potentially resulting from the vaccination, the result was no I Am Legend and vaccinations have improved since then. Still, the associated fear of GBS with the most recent H1N1 vaccine is not quite simply a surviving relic of past mistakes, but also evidence of how little we still know of GBS. As many as 60% of cases of GBS have no known causes, according to the Wikipedia article.