Today is the day! Ubuntu 10.04 LTS has been released!
For a list of features, check out the Ubuntu tour here.
A brief listing of changes (from xtemu.com):
This release will probably be known as "the one with the buttons on the left", as the default window buttons are moved from the upper right to the upper left.
Of particular note is the Ubuntu One Music Store, an iTunes alternative, which is being released with this version of Ubuntu.
For free Ubuntu downloads, click here! C'mon now, get downloading!
For those that have already downloaded the "Lucid Lynx", there are already tweaking guides or updates scripts that have been published, such as this one at WebUpd8.org.