There isn't much to say to this story that you wouldn't have already gauged from the headline. According to a report from Apple specific blog 9to5Mac, iPhone iOS 4 users will have an option to upload their recorded videos straight to Facebook in the same way that they can currently upload to YouTube or MobileMe.
9to5Mac uncovered the hidden gem after analysing some code within the iOS 4 framework. In it, it states that videos will be able to be uploaded with a maximum height and width of 480 pixels at 30fps.
This isn't a definite inclusion, it's based purely on the sources interpretation of some code so don't come crying to us if you fork out for an iPhone 4 and it doesn't have this option.
Mind you, if the sole reason that you fork out for an iPhone 4 (or update your 3GS to iOS4) is because you need to upload videos to Facebook then maybe the iPhone isn't for you. After all, it is capable of a lot more than that.