Facebook was never meant to become as big as it is today, yet despite that it is a largely used site that almost everyone knows about. They continue to surprise their users with new and interesting advancements to keep their company getting stronger and better. I imagine anything they make has a good chance of becoming a success.
With the world in a Facebook grasp, it is no longer a question of whether a Facebook endeavor will be a success rather who will end up being hurt. Facebook Home is going to try to be what Windows 8 has already become. Facebook is so integrated in society uses that this app will be perceived as a gateway app. It will succeed people will use it cause those that focus on smartphones these days, focus on the ability to upload and communicate through the social media giant. It will be successful as much as windows 8 is successful. It will be geared toward people who are not already sold on Apple's OS or Windows 8 and will fill in the gap till Google can come up with their own signature gateway app.
When Facebook was having a press conference and was showing their shareholders what to expect from Facebook's newest ideas and designs, they were less than impressed. If they cannot even get a small group of people interested in their newest ideas, I doubt that they will be able to convince a wider audience.
I don't think the Facebook Home for Android will be a success because there has been so much dissatisfaction with Facebook recently that it doesn't seem that people are as excited or use Facebook as much. I believe they continue to use it routinely, but anything new connected to Facebook seems to be met with not much interest.