The first feature Mark Zuckerberg announced, Download Your Information, lets you download all of your photos, messages, videos, etc. Simple enough! It all goes into a single zip file, so that it's all in one place, which will then be emailed to you. As for privacy concerns, you'll need to provide a password and possibly answer more security questions. Whether you feel totally comfortable having all that info passing back and forth is up to you.
There's also a new dashboard, where you'll have the ability to see what permissions are granted each application and what information it's using. It'll also, crucially, make it easier to handle your app privacy settings by making them more transparent.
The third main problem, according to Mark Zuckerberg, is making sure you're most connected to your Facebook friends that you actually, you know, care about. While he spent a lot of time talking about ways to optimize subgroups that won't work—algorithms, separate friend lists—the actual solution will be a "social" one. Translation: tagging your friends like you would a photo.
The goal is to map all real-world groups in a way that's all-inclusive and can be used in several different contexts. Facebook wants to be the place you go for group email, group chat, etc.
You can sort people by family, activities, sports teams—pretty much whatever you want. And just like anyone can tag a photo, each group can be controlled by any of its members. In terms of a design implications, Groups will live on the lefthand side of the page. You can send and receive email within the Group, even edit a document. It's not clear if that collaboration can take place in real time.
Groups won't replace your friend list, but it will be integrated across the site. Particularly, your news feed will show group activity, and Facebook Connect websites will show the activity of group members. If you don't want to be a part of a group, you can leave (which, obviously), and no one else can add you unless you explicitly say it's okay.
There are some questions left here; if I invite ten people for a group, it doesn't seem as though there's much to stop them from adding ten friends, and those ten friends to invite ten friends, and so on. The answer seems to be that common sense will save the day, since no one wants to be on a 250 person email list. You can also change your notification settings within a group to adjust how that group can notify you.
Groups themselves also have privacy settings—they can be open groups, meaning their information is public; closed groups, meaning that it's not, and secret, meaning that no one can see who is in a group or that it exists.
Despite the questions, though Zuckerberg sees an 80% adoption rate "over time." If you're among that 80%, get ready for a quick landgrab for group names. While you can call your group "Family," for example, there's only one unique address on Facebook for a group with that name. So once BarrettFamily and Barrett_Family are gone, I'm basically going to give up on keeping in touch with my relatives. Sorry, folks!
Hard to make a judgment call on Groups until actually, you know, using it, but at first blush it seems promising. Better living through categorizing my acquaintances! Then again, most of my social circles have at least one Facebook holdout—which is partly what Zuckerberg is banking on. Either a Group forgoes the convenience of Facebook for the uninitiated, or the uninitiated cracks down and joins the network. If Facebook wins even half those battles, that potentially a huge amount of growth.