This is pretty much par for the course with 90% of the 'cloud' offerings out there. This is also true with various hosted application platforms where you can ad

This is pretty much par for the course with 90% of the 'cloud' offerings out there. This is also true with various hosted application platforms where you can add a custom domain for your blog or whatever. There's just no way to ever rely on a single IP and guarantee that it will be stable for consumers, without failover. Even your ISP gives you two nameservers for that reason.