One of the most visually striking changes that came to EVE Online with the Dominion expansion is how the devs improved the look of the planets. This was no minor facelift either, it's been a dramatic change. The graphics update breathed new life into New Eden's setting -- solar systems now have vibrant gas giants as well as planets dominated by storms, ice, oceans, or lava. Most players are probably just content to see and appreciate the eye candy, but those interested in how CCP Games created these planets will want to read the "Awesome Looking Planets" dev blog from CCP Mannapi. (And just look at that angry expression!)
Although the subject of Mannapi's dev blog is somewhat technical, it's actually rather easy to follow. He walks the reader through the tools and processes CCP Games put to use in revamping planets in Dominion. If reading about height maps, preprocessing, rendering, and textures is your cup of tea, you'll probably enjoy his illustrated explanation of these facets of planetary design in EVE.