I am bumping this thread rather than make a new one about better trees.
I agree that trees should have a better growth system. Crops grow in 7 stages. So why not trees? And why should a huge meter-wide tree grow instantaneously when crops take forever? It makes no sense, or more importantly, it's not consistent with everything else in the game that grows gradually. Trees were one of the first features in Minecraft... why not overhaul them a bit??
I found this mod that does a great take on it. Unfortunately it is only supported by version 1.7.
This really should be vanilla!