Hubble has been awesome especially considering it started with a manufacturing error and had to be repaired in space. It has brought pictures of deep space that we could not have dreamed possible a few decades ago.
Plans for its replacement are in progress. The James Webb Space Telescope will launch in 2018 and will be put in an orbit 1 million miles above earth. It's primary mirror is the size of a tennis court.
This thing is going to peer back to the very birth of our universe.