One of the convention panels, "SGA as a Closed Canon", involved speculation about a possible rewatch community. During the con, I also had at least two people mention to me that they envy the vibrancy of the SGA fandom but haven't yet watched the show.
A new SGA series (re)watch community has just launched:
sga_rewind. Discussion of the first episode will begin this Saturday; please see the comm for additional details.