From what I can tell from the announcement the change will apply to a NAT gateway, so the cost of that will rise from 0.045 to 0.05, the same as having 10 IP addresses. If they are really seeing high costs associated with IPs then I would like to see them reduce the price of the NAT gateway to the same as having 3 or 4 IP addresses or less, ideally free then they would probably see a lot bigger uptake.