I have a feeling that forum activity spikes at certain times. Because this is a FF-related forum, I think things might of been a little more active a year ago because FFXII and KH2 were still relatively fresh in people's minds. Perhaps people were more drawn to the forums at these times because they are looking for things such as information and tips on the games, or for just general discussion. Since there has been a bit of a loll in FF games as of late, this might at least partially explain why things have been quiet around here lately. Things might pick up as we get closer to the release dates of some of the upcoming FF titles, such as Crisis Core, FFIV DS, and eventually the FFXIII Compilation. However this is just a theory, we'll just have to wait and see.
