Actually, I don't even think that the game mechanics itself need to be changed either. It's a great game, probably the most popular on BL at the moment. When a game gets boring it's not because things need to be replaced or changed, it's because things need to be added and expanded upon. That's how it is with just about any game, Blockland, Lotro, MC, if it gets boring then they add to it, not change it completely.
That's the whole point of expansion packs and updates and things. If this is going to be less boring, I say just update what's already there- not replace or change it completely, and add to it. More classes, weapons, bosses, etc. And perfect what's already there as well.
You guys keep spending so much time working on builds and classes and bosses and then you just throw them away because people get bored of them. Just add and update them, rather than just throwing them away like tissue.