a very good read: http://arstechnica.com/open-source/reviews/2010/02/hands-on-new-single-window-mode-makes-gimp-less-gimpy.ars
I gotta say though, Blender’s dev seems to be the fastest and most public of the major graphical FOSS projects, kudos to them.
True, but then again, blender devs don’t get butchered by 3dsmax purists making smug comments about how “blender isn’t really used by professionals” every time a related article pops up on slashdot.
If I were a gimp dev I would be a total hermit. It doesn’t matter what cool new innovative idea a gimp developer comes up with, a photoshop nerd will always hold up some feature from photoshop as grounds for invalidating everything a gimp dev has accomplished.
well, photoshop DOES do a lot more… but @ that price it’s not worth it unless you use those features all the time (which most users don’t!).
Personally, I don’t mind gimp’s window system. Infact, I got used to it in college when I used photoshop on Irix. It works the same way. 
I like spreading my windows around my multiple monitors, very handy. If gimp switched to where you had to cover both desktops with a main gimp window to spread the tool windows around, I wouldn’t upgrade (nice think about GPL software! ).
I personally hate the new “always open & never useful” main window. I’ve been having issues with it since it came out (not going to foreground & what not so I can’t open a file w/o minimizing the program & re-showing it).
I don’t mind the main window, and haven’t had any problems with it. Personally I like the GIMP, it does what I need it to do, and I discover new great tools in it all the time. The fact that the 2.8 release date got bumped up another year shows that they are giving some serious thought to the next version, it will be interesting to see how it turns out.
the biggest thing people seem to ignore is that we have different choices in the software we use! When one gets more negatives then positives in a person’s view that person can switch to something else! 
Love that feeling.