CCP's announced a new EVE expansion in Tyrannis, with this one allowing mining and structure-building on any planet in the MMO.
Said the Icelandic firm on its blog:
That‘s right, you will finally be able to survey for juicy deposits of minerals and other goodies, build infrastructure to harvest them, store them, process them and launch them into space. Build complex networks of facilities and fine tune them for optimal production. All in a very massive single shard sandboxy way as only EVE can provide. And it‘s not just the terran planets. It‘s ALL OF THEM. The gas giants, the lava planets, the ice worlds, the water worlds and even the elusive plasma planets. Each type with their unique properties. Maintaining facilities on gruesomely hostile planets will be tougher and more demanding, but the rewards may be so much more “onturning.”
There's no date on this yet, but it's going to be announced before the summer solstice, CCP's assured.
Of note: planet combat is promised in that update, but "not in this expansion".