Not even close. I own both phones and the only thing I'll add that hasn't already been said is that the HDR photo feature they just added in ios4.1 owns all...
High dynamic range imaging - Wikipedia, the free encyclopedia
Quantity of pixels is irrelevant. If they're under/over-exposed, they're useless. Digital photography has been plagued with LOUSY dynamic range since they first appeared many years ago and cmos/ccd tech has done little to improve it since then, but the iPhone4's HDR photos literally rival that of film. I'm blown away. If you were ever into 35mm film photography, you know that the wide exposure latitude is orders of magnitude better than digital. The HDR feature they just added almost bridges that gap. And NO, the "night shot" feature in the Vibrant is not the same thing.
For those who don't understand dynamic range, I could take a picture with bright white clouds and dark shadows in the same frame, if I meter somewhere in between, the Vibrant will blow out all the clouds (overexpose) and lose all detail in the shadows (underexpose). The iPhone4 with HDR turned on will perfectly expose all of it, the way any decent photographer would want it. No post-processing needed, just perfectly exposed pics. It's almost worth buying it just to use as a freakin' camera. Samsung really needs to implement HDR too.