Pretty much the same as before. Only the button moved to a new location.
In the top bar, it is the right-most button, with the icon that looks like the SE logo. Clicking on it will open a menu which tells you which site you are on, and what are your communities, and what are the available sites.
There you can choose to log out, again, as the right-most ...
As mentioned in a comment this is to draw your attention to the fact that there are relatively many pending review tasks.
Thus, if you see it and are willing to help out click on it to visit one of the review queues.
The details of what relatively many means are explained in this answer: How does the review-needed indicator work exactly?
This site is in ...
We had problems with a datacenter test that left our caching layer in a partially broken state.
All issues should now be resolved.
See also https://meta.stackoverflow.com/questions/268957/topbar-notifications-dont-go-away
Update: SE was not deaf to the flood of complaints about the color. At first they made the color a tiny bit lighter (from #212121 to #2f2f2f), and then, upon a suggestion from SciFi, made it completely black but slightly translucent: rgba(0,0,0,0.8).
Not quite as black anymore. Feeling better?
One more thing that's not mentioned often: there is no easy ...
You lost two points for an approved edit suggestion when this question was deleted (by Community♦) earlier today, so your reputation change of $(+5) + (-2) = +3$ was indicated in the top bar.
If you check the "show removed posts" box at the bottom of the reputation tab of your profile, you should see a notification of such events there.
Today, a new topbar was rolled out. One of the changes is the location of the site-switcher, which is now on the right. The Stack Exchange logo on the left now takes one to https:/stackexchange.com. The change is not universally loved.
The indicator for pending reviews is only shown when the queues are above a certain length. I do not know the exact value off-hand for this site (it differs per site), but it should be around ten, and at the very moment there are only three review tasks so we are below that threshold and thus it is not shown.
You can still access the queues by clicking the ...
It seems to have been corrected more or less. It shows 30 reviews now, and through private browsing window it adds up to 25 reviews.
I don't know if it's because I did a few reviews, or if something else happened. Probably the latter.
In the comments, some users asked about a Firefox analog of the above. A popular Firefox extension for managing user stylesheets is Stylish. Several stylesheets for the top bar, some specifically designed for Firefox, can be found at Gallery of custom styles and/or scripts for the top-bar.
Apart from extensions, most of today's browsers have built-in ...
It got added as part of a feature request on Meta. I asked one of the guys to help me dig it up: Bring back review numbers to the top bar
The accepted answer was posted on the 17th, so I assume that's around when it started. It also adds that the item is for suggested edits only, but they may roll out a new thing after New Year's that is more generalized.
Here is a modification for MSE of phils's answer in Post No Bills's link. This works with "Stylish" on Firefox:
/* domain("mathoverflow.net") /* for MO */
In my browser (Firefox), I can drag either link (from the "StackExchange" menu or the "help" menu) to my bookmark bar. Also, right-clicking on either link might allow you to move the meta link to the bookmark bar.
Speaking as someone whose job frequently involves flipping back and forth from the meta site and the main site, needing to use two clicks to go in either direction is bothersome. We added it to the "help" dropdown in the top right to make a more consistent option than the top left, but it's still two clicks.
Mad Scientist is right, though - in its design, ...