I signed into facebook from a friend's iPhone yesterday and notifications finally started working for me as well. I have an original Droid running Android 2.2 ever since the first facebook release that included push notifications and they never worked for me. Same with my XOOM and now my Rezound. Now, the notifications started working immediately for me yesterday after signing in with the iphone. I have been using Friendcaster Pro, which also wouldn't support push on my Droid or XOOM, but it's been working on the Rezound. I noticed when signing in with it, it asks facebook for permission to manage notifications. Not sure if it should (or if it matters), but the official facebook app never did that.
For whatever it is worth, I also don't see Facebook for iPhone or Facebook for Android in the list of apps authorized to interact with my facebook account, but the notifications are indeed working, at least some of them are anyway. I'm getting notifications when someone writes on my wall. I'm not seeing notifications for when people like my status or posts or when close friends update their status or post links. Those are the only test cases I have.
Just for $h1ts and giggles I sent an email to facebook developers before trying the iPhone thing, but I don't expect a response...