No it's not the difference is no history of fraud and a sound business model.

I'm not saying that I am certain it will happen or this is really a sample card of the real thing. (the picture was posted without comment) What I can confidently say is that bitinstant is more transparent than BFL in their proceedings and I consider them more trustworthy.
It could turn out to be publicity stunt of some sort, at the worst. But until is see some indication that it is I maintain that it is a genuine product.

Reasoning: No preorder requirement no special commitment required no direct profit to gain from the company if it doesn't happen. Even if the product trurns out to hit a roadblock I think there is a genuine effort taken to bring it out.