Here are ideas for 1.9 and 2.0 of the PC version.
1. More Ores: I know this is a bit unoriginal but I want it in as we have only 7 or so ores at the moment, here are my ideas in a mini list,
Rubies: slightly stronger than Diamond
Sapphire: slightly less strong than Diamond
Topaz: Orange in color and slightly stronger than Iron
Amethyst: Slightly less strong than Iron
Jade: Highest level of strength, far above Diamond, design is like Emerald but in the normal ore style of design. Replaces demand for Emerald Tools as essentially is is what everyone wants in Emerald Tools but a different mineral as Mojang would want to keep emeralds to just trading purposes.
Lead: Right in between Iron and Diamond, color is a dark grey.
2. Minecart upgrade: minor change, but main edit is allowing to connect minecarts with chains crafted with 3 iron bars in a vertical line.
3. Ender egg use: Being able to hatch a dragon and fly around on it after placing the egg in an area by a heat source like a torching and waiting a full minecraft day with a timer at the bottom of the screen, you have to be near the egg when it hatches so it thinks you are it's mom, but if you are away when it hatches it turns into the boss and you have to defeat it and get another egg and start over after rebuilding everything around where you put the egg.
4. Ores in the Nether and End: I know there is quartz in the nether but that was a bit of an excuse and I know this goes with my first idea but at least one ore per dimension (or 2 in the nether but like I said, quartz is an excuse for the demand), designs are,
1. Design is a light green, in the nether, in between Ruby and Jade.
2 Design is a bright purple, in the End, slightly stronger than Jade, a reason to go back to the end after defeating the dragon and possibly making an enderpearl farm.
So what are your opinions on the list I made? Some ideas are unoriginal (well most of them at that) but I am thinking about what Mojang's intentions are and the originals ideas like the Emeralds as i am pretty sure that Emeralds are going to be left to trading use.