This is the collective dream of the GIMP community about a roadmap for future GIMP versions. It is not meant as a place to keep a wishlist - have a look at
http://bugzilla.gnome.org/browse.cgi?product=GIMP (we will call this "reality") for this.
If you're frequently having lucid dreams (aka "contribute to GIMP"), you may add definite dates to your and other's dreams, but will be held liable by the sandman if you miss them.
Dreams by version
Please be careful if your dreams often leave linear time.
GIMP 2.4
color management
usability
pygimp on all platforms (done)
performance improvement
add zoomable previews to plug-ins
GIMP 3.0
higher bitdepths
more colorspaces
DAG-based image processing
layer grouping
adjustment layers
filter layers
shape tools