Wow, it's nice to see a forum user that isn't pure concentrated acid. There was a large void between my old activity and my current posts as well.
The best person to ask about how the forums has changed would be Otis Da Houskat. He's been here since 2005, and he's still quite active both on the forums and in the game.
Regarding the game, the following has changed:
-We now have shader options to make the game look fancypants
-We no longer have terrain because of the implementation of shaders. (stares at kompressor)
-We have a "replacement" of RTB called Blockland Glass. I don't really know too much of the details, but that's a thing. I live under a rock.
-You can still use the original client version of Blockland, but there's now a Steam version. That means Steam Overlay, which means you can take pictures using a steam shortcut, which means your snapshots are stored on steam, which is automatically better somehow.
In terms of the forums, it's just gone downhill.