Home is a new home screen for Android phones. After the phone has been started up Home takes over the home and lock screen and shows your FB feed. You still have access to the other apps on your Android, but the access goes through Home.
Home integrates some of the well-known messaging services like SMS and FB messages with the FB timeline, and hence one big advantage that Home offers its users, is integration of messaging in a Facebook device. It makes your phone FB-centric.
Home seems to be a great idea for the Facebook company. The user will think of his device as his Facebook. We'll soon be hearing "Oh dear, I left my FB on my desk!", instead of "Bugger, I left my mobile phone on my desk!". You'll think of most things you do on your smartphone in terms of FB and its user interface.
Everything you do on your FB phone will be known by Facebook, and that includes anything you do inside the other apps, including your banking app. That could mean FB will know what you own, earn and spend. It will know where your money is and how much you own, where you earn it and where you spend it. I'm speculating of course, but is there anything to stop them?
Facebook's revenue comes from advertising. To advertisers, customer information is the most valuable thing next to money. But is FB any less trustworthy than Google? Does Google spy less on Android users than will Facebook? I think Google knows less about its users, because they don't know the links between people as well as Facebook does. They would know more about its users, and as much as Facebook does, if Google+ would take off.
Would I want a phone with FB's Home? I'm not a great FB user, so my answer is definitely no. And in any case no.
Facebook writes: "Home is a completely new experience that let´s you see the world through people, not apps." That is not going to turn me into a Home fan. To me a smartphone is much more than FB, SMS or Email. It's about surfing the web, playing games, navigation, taking notes, dictionaries, music, film, camera, Twitter, RSS-feeds, todo, news; all those things that apps provide in all their diversity. To me Facebook is one app among many others.