In 2007, I formalised these three layers into hardware, framework and software. I used the following diagram at various conferences (from Web 2.0 to OSCON to FOWA) to describe utility computing as the transition of the computing stack from a product to a service based economy.
So, I was not that surprised to receive a very tongue in cheek email telling me that I was wrong about the cloud because it is a triangle (see diagram) .
Apparently the source of this triangular insight is Michael Sheehan's post.
Oh no, did I got the colour, shape and names wrong? Who cares, it's not important unless of course the Appistry joke about Michael trademarking the triangle becomes true. In this case just use the rectangle (it's prior art and creative commons).
Alternatively, why not have a go and try experimenting with circles, dodecahedrons, the colour purple and paisley? Believe me you can't make any more of a mess than today's thought leaders.
As for my predictions for the future of cloud in 2009/10. Well, more and more analysts will start talking about the shift of IT from a product to a service based economy, there will be increasing user pressure for second sourcing options and growing demand for standards at various layers of the computing stack based upon operational open sourced code.
Don't ask me what name or shape it'll be, but as for the colour then judging by how much conflict there is in the cloud I'll take a stab at blood red.