80 million Facebook users will be getting a new long-planned design tonight. A simplified design provides easy access to your entire Facebook experience.

Facebook says, The new design is basically what we’ve been examining in detail since the first test screenshots appeared last October.

App-driven updates from your friends also show up in the stream, so it is a very good way to keep up with what’s going on in your circle. And thanks to the new prominent filter function, it’s easy to see just the updates from people in your networks. This is like the mythical “groups” feature that Twitter users are waiting for. You can easily see just the updates from people at your company or school, or from a particular app, and then pop back to the full feed and see all your friends. I like the ability to hide updates from contacts I’m not especially interested in.

One nit: Although Facebook calls it the “real-time stream,” it doesn’t auto-update. You have to refresh the page to get the latest. But overall, this is a strong update for old guys like me who want their Web services simple. It puts your friends more in front of you than the old design did, and that’s what Facebook is really about.

There are a few other new points that the company revealed today. The news feed will now be more clearly delineated at the top. “Credits Balance,” as we noted in an update to our last post, now appears in the drop-down of the new Accounts page on the top right-hand corner. The new search box shows search results for people based on how closely they’re connected to you — how many friends you both have in common, etc. The photo uploader has been rebuilt from scratch, and promises far better performance than the prior one.

While notifications have been moved up to the top, and bookmarks slotted into the left-hand navigation column on the home page, Chat is a little different. The instant message service now appears beneath the new bookmarks section on the home page, and shows you friends who are online and available to chat; the list is sorted by how often to talk to the people, and other factors. Meanwhile, a part of the bottom toolbar is sticking around — pop-up window on the right side of every page, where you chat with people as you use various parts of Facebook or third party apps.

Parts of the site that were formerly located in the bottom toolbar — bookmarks, notifications, chat — are now being moved up into the left-hand navigation column on the homepage, or into the top navigation bar. Here are some more details gleaned from Facebook this evening.

First off, a lot more people are engaging with notifications in the new design, Facebook’s Peter Deng tells us, which isn’t surprising since it’s at the top left-hand side of the site instead of the right hand of the bottom toolbar. Notifications for third parties will appear within the new interface for the rest of the month, until Facebook removes them on March 1.