Amazon (AMZN) plans to lease two additional Northern Virginia data centers in an effort to improve the scale and reliability of Amazon Web Services' pivotal US-East ops. US-East, estimated in March to host 70% of AWS' IP addresses, was hit by multiple high-profile outages (I, II, III) in 2012, something that led many clients to question their dependence on AWS. A 200K sq. foot data center could go live in Q4, and construction is expected to begin on a 115K sq. foot facility in mid-2014.