I don't think minecraft will ever get.. "to complicated".
Essentially when people start playing the game they don't do it because they want to make potions, or create a redstone circuit. I'd bet that the majority of people play because they want to make a fort, or a house. They can do that without learning about everything in the game.. However what all this extra content does offer people is more and more things to do, so instead of playing the game and making a house and getting bored, you are continually finding more things out making the game more interesting to people that have played the game for longer.
Essentially if you want to play basically the concept is still there, you can still dig dirt and mine diamond and make a wooden house, just like you could in the beginning, but now there is that little extra for those that want to explore further and making the game more deep.