Honestly, I personally don't follow any of PC's social networks. They don't really provide anything that I would see faster than browsing the forums and seeing the announcement splashes that get posted on the top of the forums. Just from glancing at them very quickly, it also looks like they aren't updated all that frequently either.
I don't really have any specific suggestions, but if they were managed a bit better to be kept clean (Especially the Facebook page, as half of it is spam asking about ROM Hacks), and maybe the Twitter could post about site-down times as they're happening (I see that it's been done, but there are MANY more than were tweeted about), maybe that would be more useful. I guess it would provide a way for members to see if the site is back up without bombarding the server while it's trying to recover. Of course that's also a lot to ask, as not everyone has these social networking sites either.