Interesting, I actually work on a large scale private cloud storage product which sells primarily to enterprise and government. Customers cannot get enough of it, and there is definite move away from traditional enterprise data storage using SAN/fibre channel and block storage over NFS, towards object storage on commodity hardware and HTTP/REST. AWS protocols are becoming the standard everyone uses for HTTP data, as it means applications built for S3 can usually just be pointed to a new endpoint. I do wish there was a real effort to standardize this however, because most vendors only really support a subset of the options and headers, especially stuff like versioning, multi-part-write, and Amazon has changed their spec numerous times already.
From what we've seen with our customers, there's some initial heavy lifting around virtualizing your infrastructure, but once the infrastructure is running OpenStack, using it is remarkably similar to AWS/EC2
Interestingly, we tried using 'aws' instead of 'ec2' as a keyword, but the noise level around it was way too high. Results included GPU applications, the wireless spectrum, and the American Welding Society...
Great article, excellent interpretation of the google trends data. As a search marketer I concur with your findings and I think you are spot on in the interpretation of the google data.