We are currently focused on startups in the states but definitely sign up if your team is talented. We do get approached with quality gigs both in the states and overseas.
I think the real question is, does the startup have to be registered in the US?
For instance, I live in Jamaica, but my startup is registered in Delaware (with a full blown US presence - bank account and all).
Would I 'qualify' given that I could be considered remote (i.e. use Skype and communicate via email)?
I can understand why you would want the Projects to be US-based (quite frankly, that's what I am looking for), but I don't see why the team would have to be US-based.
A concern employers have with teams outside the US is the time-zone mismatch. Because Jamaica doesn't have this issue, and your company is registered in Delaware, definitely sign up.