Now that the tabs aren't on top, there isn't the convenient handle on the sides of the tabs that allow you to drag and drop a tab from one window to another...
Right, because it's so much more convenient to have to click on the tiny corner of the tab as opposed to just grabbing any part of it.
sigh Apple. I really liked the tabs on top -- you could pop in single Safari windows into another one to set open 2 tabs.
Why do people seem to think this functionality is gone? it still works just like before. Just drag a tab from one safari window and drop it into a single window, and presto: two tabs in one window.
I wish there was an option to have the bookmark bar replace the title bar. It would save as much room as ToT and honestly I wouldn't miss the title bar at all.
Until you want to move the window and start clicking bookmarks...