I don't know whether Obama was born in the US or not, but either way, he is clearly an American now, so what's the big problem, other than some outdated law? Lots of countries have presidents that happened to be born somewhere else, for whatever reason.
I don't like Obama much either though, but this seems like a silly detail to be concerned about.
At first I thought the guy in the video seemed very amateurish, but when he got to the bit about the layers and the colouring, he clearly has some good points. I like using Photoshop, it's quite similar to Illustrator.
Probably they were just touching it up the birth certificate, not faking it.
If it really is faked, then; what a sloppy and poor job!
I am sure there are 13 year old kids that could have done a more convincing job.
What a bizarre thing!