It's a major departure from the existing look, feel, management, and operation of Pages today. There will undoubtedly be more information released throughout the day (after which I'll update this post) at the fMC in New York this afternoon.
So what are the biggest changes with the new design?
Demise of the Default Landing Tab
This is probably the biggest change and the one that's going to give brands a scare. Currently, every Page has the ability to set a default landing tab as the destination for non-Fans to land on when they visit the Page. Fan-gating - the technique in which a Page admin required a visitor to become a Fan before gaining access to that tab's content - will be become a thing of the past. Also, it will be much more difficult to tell a brand story in one clear spot on the Page.
Default landing tabs were treated as microsites by many brands and were successfully used as content hubs and navigation aids, especially when a brand had multiple (perhaps localized) Pages. This model is over. Page admins are going to have to ensure their content is shareable, not just interesting. People are not going to visit Pages to engage as much as they are going to incorporate Page content into their own News Feeds and Timelines. In one sense, this is going to be a potential pitfall for Pages that have strong communities in place. The Wall, though discoverable in the new model via a link that NO ONE will ever click, was great for this because of its board-like interface. In another sense, this change is going to make content more likely to be seen in the News Feed, increasing Organic Reach and Talking About This numbers, exposing Page content to a much larger audience. The new Page model is all about pushing content distribution, not curation, and certainly not aggregation.
New Admin Panel
Admins of a Page will now see a new Admin Panel at the top of every Page they administer. The most important part of this panel will be the new messages interface, which will allow admins to reply - privately for the first time as the Page (not as a user account which could simply message Fans in the past ) - to messages posted to the Page by users. There is also a Notifications section that shows current Page activity, a marginally useful 'New Likes' section showing a selection of the latest Fans, and an Insights overview graph that shows recent post activity, Talking About This, and Reach curves. There are some helpful links at the top of this section but probably not that big a deal for most admins. It feels like a 'filler' feature rather than a 'killer' one.
Private Page Messages
This is potentially a big deal, or a big nightmare, depending upon the brand or Page. Let me explain. In the past, the only way to get a private message (meaning not on the Wall for all visitors to see) to your Fans was to change to using Facebook from the Page admin account to a personal account to send a message. But this was terribly inconvenient. As an admin of too many Pages to count I can personally say that this resulted in exposure to hundreds of unwanted friend requests. Page Admins have always wanted a way to communicate with Fans and visitors privately and this will allow it. . . with a few major caveats. First, though the messages sent will come from the Page, they can't be sent proactively as that Page. The Page can only reply, not reach out. Second, for brands that have a large support community on their Pages (think software e.g.) this feature could be a nightmare. It's yet another location where they have to manage support questions or deal with angry customers. Techcrunch said it best: "You’ll need to consistently monitor and respond to messages though, or you’ll risk being perceived as ignoring your fans." This could be a very big problem for already-overwhelmed community managers. I mean, it could, like, seriously cut into their Pinterest time.
Timeline Canvas Applications
These. Oh, these. These are the sadness. The way Page apps / custom tabs are now shown in the new Pages Timeline interface is likely the biggest letdown of the new Timeline. Remember the top row of tabs that showed clearly what apps your Page had? Me too. Then Facebook moved them to the left navigation section under the profile pic on the Wall where they live today. And we saw our organic engagement numbers for all but the default landing tab app (see above) plummet to 0.6% of previous numbers on average. Now it's become even more challenging. They've been moved to four small thumbnails in the About section below the literally page-overwhelming 'cover photo' above them. But wait, there's only three. Photos snags the first slot, always. Don't have photos for your brand? Get snapping.
But there's a bright side, though it's going to require a steep learning curve for non-technical, non-code-savvy marketers. This bright side is that apps are going to have to be truly ENGAGING. Apps can post to Timeline and create dynamic, large views of app-specific content. The potential here is limitless. The problem is that creating content that users give a damn about that does NOT require them to authenticate an app is going to be challenging, especially for non-traditionally interactive brands. As of March 30, the only way users will see your apps is to search them out on your Page (they won't), are directed there by a Facebook ad, or via a shared direct link.
There's a lot more coming, of which the most interesting being the new Reach Generator which will take posts you choose as 'Featured' from your Page and place them on the Facebook Home Page, potentially increasing your reach drastically (from ~16% to ~85% per the fMC keynote.) More on this later.
Hope this overview gives you some sense of what's coming. Don't worry, you have until March 30 to comply. =)
UPDATE: check out this post from my friend and author of Twitter for Dummies Leslie on her first thoughts on Facebook's new Timeline.