Well, as far as Add-Ons goes, we've kinda hit a ceiling. There's nothing more in the way of special unique content. Many of the innovative mods are being kept privately. Coders are getting pretty stingy these days.
Not sure if you were around for it, but GSF Ghost's IS Mod has become well-versed.
Terrain Bricks are pretty common and everyone is getting pretty skilled at using them.
A lot of great ideas are coming through S&R, but near to no one is doing anything to help get them done, often questioning "Why would we need this?" and leaving it there.