Floating IPs, now renamed as Reserved IPs, are a highly available infrastructure feature that allows developers to associate an IP address with a different Droplet in the same datacenter. This enables customers to set up standby Droplets, ready to receive production traffic at minimal downtime. Floating IPs can be used for failover situations and also for application upgrades, making it easier to spin up new Droplets, run upgrades on them, and then switch traffic flow. The feature is free to use, but there's a charge for unassigned, reserved IP addresses due to IPv4 address shortages. With the addition of Floating IPs, customers can enjoy high availability, automatic failover, and smooth upgrades, making it easier to build reliable production environments.