Forrester's Hammond said the real question is, why now? He hypothesized that it's because many customers have already seen "great success" replacing operating systems, like Linux for AIX, Solaris and Windows, as well as app servers like Tomcat and JBoss for IBM WebSphere and Oracle WebLogic.
Hammond noted that data management and virtual machines are the next two product categories where companies spend a lot of money on commercial software, and are not happy about it.
"[It's a] classic attack of adjacent markets, in this case with customers ready to consider product substitution," he said.
For its part, it seems clear that Amazon plans to stop at nothing less than total dominance.
"Our goal is to have every company run all of their businesses and all of their applications on top of our technology infrastructure platform," Jassy said.
— CNBC's Jon Fortt contributed to this report.
(CORRECTION: This story was updated to clarify Amazon's comments.)