Good info but It looks like this has changed:
Amazon.com, Inc. AMAZO-ZL4 (NET-54-230-0-0-1) 54.230.0.0 - 54.231.255.255

But wow, look what Apple is using now for my icloud backups:
CIDR: 17.0.0.0/8
NetName: APPLE-WWNET
NetHandle: NET-17-0-0-0-1
Parent: ()
NetType: Direct Assignment
OriginAS:
Organization: Apple Inc. (APPLEC-1-Z)

Looks like somebody's got friends at ARIN...