I think minecraft is still as fantastic as the day it came out. The game is far far far away from dead. A dead game is one no one plays anymore, or is so old that people forget about it.
Minecraft is a game many have heard of and no one will forget about for ages to come.
As for a minecraft sequel? I would say it is a little too early to talk about that. The game keeps me plenty busy as it is. I have had minecraft since alpha and have played classic before then.
If you're burnt out that's your problem. There is so much to do, infinite world infinite possibilities, if you can think it you can build it and make it happen. That's why minecraft is so great. It is completely normal for a game to lose it's hype as it ages. That doesn't mean the game is obsolete, people's interests are fickle and sway with the wind. Hype never lasts forever.