Finally, the new much anticipated version of the gimp with single window
mode has been released!
That means that windows users will no longer struggle with that weird multi window design that the gimp used to have.
But, you'll have to set it as a preference under the "windows->single windowmode" menu. I also recommend changing the zoom preference, by default it changes the window size if you zoom, but you can change that setting in the preference menu.
Get it here: http://www.gimp.org/downloads/
Besides this change, they've also migrated more stuff to the new GEGL engine.