If you want 99.999% uptime, use Azure TrafficManager and set up failover loadbalancing to different datacenters.
We have failover loadbalancing running between multiple datacenters, no issue here!
edit : 99.99%
We have failover loadbalancing running between multiple datacenters, no issue here!
edit : 99.99%
Do Microsoft say this about Traffic Manager or are you suggesting you have to pay for extra services to get the advertised reliability figure?