Question: Why do Special Pages display in the Admin Dashboard even if you didn't use the link in the Admin Dashboard to get to it?
Admin Dashboard is meant to organize all of the tools on a wiki into one central place, to which you can always go to have all of the available tools at your disposal. Previously, even if someone gave you a link to a specific special page, you wouldn't know how they found it or where you might find other tools. You had to learn by word of mouth about Special:SpecialPages, and there was no way to get back to the master list once you were on a specific Special Page. Placing the Special Pages (read "tools") into the Admin Dashboard allows consistent, constant access to that central area where all tools live, from any "tool" page you are on. This behavior should always be clear, whether you access a Special Page directly from the Admin Dashboard, or by some other means. The idea is for there to be one central area where all of the tools of a wiki live, and where all of these tools link back to the central organized area -- Admin Dashboard.
Question: Why did you mess with Recent Changes?
We did not change any of the content of Recent Changes, the log remains exactly the same as it has always been. If there has been a change to that log, it was not intentional, and I ask you to please report any unintentional changes to Special:Contact so they can be fixed. Recent Changes is a tool and per my explanation above, it should be displayed in the Admin Dashboard. It seems clear that Recent Changes is more useful with a search box in it, so we are adding the search box back to Special Pages ASAP. We also felt that some Special Pages like Recent Changes are best viewed at full 1,000 pixel width, which is why there is a vertical drawer on every Special Page that allows you to minimize the sidebar. It seems that bar can be more prominent, and is not working in some cases and we are fixing both of those issues ASAP.
Question: Why show the sidebar on every Special Page?
We want to give the option to show the sidebar on any Special Page because Special Pages are now a part of the Admin Dashboard, just as the sidebar is. For those using the Founder Progress Bar, they want to see the next available tasks from any Special Page. Also, we would like to add more tools to the Admin Dashboard in the future, some of which I hope will be tools you would like to be able to access from any Special Page. If you don't like having it there, use the vertical drawer to minimize it.
Question: Why does the Admin Dashboard not pull theme color?
As part of the process to make tools different from content pages, and consistent, we chose to implement universal theming to the Admin Dashboard, much like the new visual editor has done. We've heard some feedback that the white background under the icons is particularly jarring on dark wikis, so we are considering pulling wiki page background color for that area in the future to help resolve that issue. The Admin Dashboard header is it's own consistent color and will likely remain that way in order to keep the needed aspect of consistency and intuitive clarity for what type of page you are on.
Question: Why isn't this optional?
If there are concerns about how this tool currently functions rather than just writing it off after one day and removing it for people or wikis, we will be seriously looking at all feedback and improving the tool so that it is the most helpful it can be. If it's disabled for some of our most passionate wikis and users, your experience would be different than any other wiki and in the future you would not be able to reap the benefits of new tools added to the dashboard and other changes that will be coming along with this. Also, making this the most useful it can be means we need your help in giving feedback about what would help you - which you can't give if you don't have it enabled. Bottom line? This is meant to help, and where it's not helping we will fix those issues so it does, rather than just removing the whole feature.
Question: Why are the Special Pages "squished"?
The Admin Dashboard sidebar now shows on all Special Pages displayed within the Admin Dashboard. That doesn't mean you have to keep it there though. If you think a Special Page looks too squished with the sidebar, you can click anywhere along the vertical drawer (the grey line that runs along the length of the Special Page with the arrow in it) to minimize the sidebar and view the Special Page at it's full 1,000 pixel width. We realize that some people feel this option is not prominent enough so we will be making a couple of small design changes to make it more obvious.