what most likely would happen as most of these agreements is full reciprocity. i.e., like Europeans have to pay $14 for the ESTA visa waiver to travel in the US, Americans would have to do the same and register online.

That visa waiver would hopefully work for the entire E.U.

Or, like Australia, Brunei, Japan, and Canada which were similarly notified and implemented the changes, the US will do the same.

http://www.independent.co.uk/news/world/europe/europe-visa-f...