The upcoming QGIS 2.0 will have some really cool and useful new features. Check for example out the latest blog posts by Anita Graser aka Underdark, where she takes you on a tour of all the new features of the all new print composer. There are six posts highlighting the following new features: guidelines, multi-column legends, overview maps, html labels, map grids and rules and guidelines.
At nyalldawson.net you can read more about the upcoming ‘blend modes for layers‘. These effects, previously only found in photo/image editors like GIMP or photoshop, will allow you to blend layers together using various effects. Another feature you would normally expect in GIMP or the like is colour control for raster layers. This allows you to tweak the saturation, hue, grey scale, etc.
There is a lot more coming, but these changes alone are really impressive!