Linux -> EC2
Mysql/Memcached -> S3/SimpleDB/Queue
Apache/Asterisk -> HTTP/Mechanical Turk
PHP/Perl/Python -> REST
The shift is from a defined technology to mode of operation. I could replace operation with service, but frankly the word is overused at the moment.
The above also focuses the attention on Amazon, when really it is about meeting a need. It just so happens that Amazon at this point has the lead.
Google is skipping the service business and building applications at this point (aka value add).
Why just store data when you could instead turn it into a spreadsheet?
Google Apps is damn sexy for a company just starting out. Once they roll out their Contacts App which eats away SaleForce and then sucker punches QuickBooks they become a one stop shop.
Amazon wants to be the provider. They should be able to leverage shifts in hardware and software to their advantage.
In theory this means the next competitor of Google will be launched from some sort of hybrid hosted/AWS system.
If the FreeBSD guys leapfrogged Linux next year, it would not matter to Amazon. Both run on EC2. VM Ware has been taking this same route inside of the enterprise by trying to make the OS irrelevant.
They need to leverage the services and learn how to be leveraged by the services. The real winner is the tool that becomes the ubiquitous component in service stacks.