A few weeks back Peter Coffee wrote a piece is SDTimes titled Cloud Platforms for Profit. He works force salesforce.com and has a few interesting perspectives on cloud computing and its effect on software development.
He starts off with a discussion of the increase in complexity and latency in the development process when using locally based computing and how the movement to a more elastic web-based approach caused a shift in perspective for him.
He then goes on to talk about how cloud techniques are allowing organizations to focus on business value generation rather than the underlying infrastructure - freeing up their team to do more with less.
The article is useful to look at but a bit naive on the data transfer issues related to cloud (since applications almost never standalone), but that may be alright. He also doesn't really talk about the different levels of cloud but focuses more on the attributes that work for the organization and the objective they are trying to meet.
I thought it was worth the read.