You know what the super not cool part is? Tons of Android phones come pre-packaged with a Facebook app that you can't delete unless you root your phone.
Several carriers still ship Android 2, specially for cheaper phones (or stupid phones, like Xperia Play that only supports Android 2...)
Oh, and my Xperia Play came with Facebook for Xperia that integrated a lot with it and I almost bricked the phone trying to remove it, needed to do some warranty-breaking stuff to re-install a firmware from scratch.
I supposed I could have googled it to find out, but I've certainly never had a carrier tell me in advance what apps would be on my phone. Perhaps it's buried in the fine print that I agreed to without reading, but honestly I doubt it.
Every Smartphone comes with certain pre-installed apps that you might not necessarily desire. But facebook certainly never was one of them. At least none of the Samsung series comes with it.
I just purchased a Motorola Defy XT from Republic Wireless and it came with the Facebook app pre-installed. I immediately checked for a system update (which there was one waiting), installed it and the FB app went away. Usually it doesn't work out that nicely though. My last Android was the HTC EVO and you couldn't get rid of FB unless you rooted it your phone.
The Google Nexus One had Facebook force-installed; (I think) it came with one of the OS upgrades, which is even worse than pre-installed, because I really had no choice.