a methodology for cloud computing architecture - part 2

[Ed: the diagram shown below has been updated; see previous diagram and the discussion update.]

Thanks to many people who gave their feedback – publicly and privately – about the diagram in my previous post. Apologies to RightScale and others for inverting their placement. I definitely want to recommend John Willis for an excellent overview of the vendors in this space.

Will keep attempting to articulate this until we get it right :)

• I really wanted to avoid virtualization. However, it looks like that's a foregone conclusion.
• I prefer to place the cloud layer atop the grid layer. Several good resources disagree on that; the two terms flip-flop.
• Our "3x" sidebar about TCO and AWS was quite interesting. Would like to hear more from others about how they estimate that metric.

Another note: our firm is decidedly in the camp of needing more than one cloud. For a variety of reasons, some applications must live in our own data centers. Others are great for running in AWS. Perhaps others could run on additional grids – secondary services are compelling, even if not the most competitive yet on costs. In other words, probably not as replacements for AWS, but to augment it.

Mostly, I'm interested in software solutions which can place a "cloud manager" layer atop our own equipment – so that we could pull apps from one cloud to another depending on needs. Labeled "5" in the new diagram.

Comments are welcomed.