The fact that Google is able to achieve good write performance with standard Paxos over wide areas is a direct result of their advanced network infrastructure and low latency data center interconnects. I imagine there are lots of people without a Google-class network who would benefit from WPaxos or something similar.
Does google (assuming Spanner) really use Paxos across WAN?
My understanding is, it does Two-Phase-Commit (across WAN) over fault-tolerant objects (located in a Paxos Group). Paxos Group could span across Data-Centers, but there it just uses normal Multi-Paxos -- perhaps with some extra leader election tricks.
