29 Oct Admin bar
Coming up in 3.1 is the additional of the admin bar, similar to the one that runs on WordPress.com. Actually, it's more than similar, they really did just pull it from wp.com and clean it up a bit.
While I think it would drive me nuts on a single install, when you are running a network of sites, there's a couple handy things that will make your job as a Super Admin that much more super. Kinda like added enhanced super powers. 😉
Now you, as Super Admin can easily access the site's Dashboard, the site's options if you need to edit something, or even mark the site as mature (keep out of public listings) or spam it.
There is also a Snack Menu which is a flyout of all the regular menu items in the backend of the site you are on. Old timers: note the choice of icon. 😉