http://techblog.netflix.com/2010/12/four-reasons-we-choose-a...
The problems [Amazon] are trying to solve are incredibly difficult ones, but they aren’t specific to our business. Every successful internet company has to figure out great storage solutions, hardware failover, networking infrastructure, etc.
Their third argument for virtualized infrastructure was "We're not very good at predicting customer growth or device engagement", which strikes me as a compelling problem to solve. Having to change their approach to managing service dependencies and failures doesn't seem like too high a price to pay.
This is not Netflix's core competency either. This is the core competency of a CDN. If you have problems like this, you should almost certainly hire one, and architect accordingly.
Netflix has long since done so:
http://blog.streamingmedia.com/the_business_of_online_vi/201...
I say "feel" advisedly. I don't have inner knowledge. It's just that the explanation up to this point doesn't seem all that compelling; for what seems like rather dubious benefits it seems like they've taken on an awful lot of risks they have little ability to manage themselves.