The code refactorings and clean ups that have been made to enable single-window mode to be implemented has also resulted in improvements to multi-window mode. The most significant is the support for multi-column dock windows, as you can see used in the screenshot above. People having dockables on one screen and an image in full screen on another will probably find this useful, for example. Before this, you could only have one column of dockables inside a dock window.
I also have a fundamentally different but arguably a more important announcement. There now is a schedule for GIMP 2.8 development and thus also an estimated release date, which right now is 2010-12-27. Creating a schedule was not completely uncontroversial. People pointed out that if we have an estimated release date it will surely be misinterpreted as a definite release date, and if we don't meet it, people will be annoyed. People will probably misinterpret, but that is less worse than the current situation where people speculate about dates that are way too optimistic, giving the impression that we are constantly delayed. Besides, without a schedule it is very hard for us to take decisions on what features to include and what features to not include in each release. I think that in the end having a schedule will only have a positive impact on development.
And finally, thanks to Alexia Death for letting me use her graphic in the screenshot above.