The evolution of the cloud market is a little more complex than this article suggests. As someone else has already stated, revenue is not profit; the fact that Amazon can sell IaaS at a loss by undercutting everyone else doesn't make for a long term business model.
Another analysis on this site looks at the long term trend where IT spend is shifting back to the lines of business and away from IT (http://forums.theregister.co.uk/forum/latest/2014/12/15/cios_grip_on_budgets_loosened_by_shadow_it_says_survey/)
It may be a generalisation, but lines of business want to buy the fully managed solutions offerred by SaaS, not the toolkit offerred by SaaS. IaaS is here to stay for certain classes of applications, but for mainstream corporate IT, it simply doesn't make sense. Business execs want ERP, HR, marketing and many similar core applications to be low cost, and need minimal capital investment. IaaS may reduce hardware cost (although hardware is dirt cheap these days compared to either software or services) but the capital investment required for build your own software, and the operational costs of operating low level IaaS just doesn't stack up.
For sure IT loves IaaS - it supports their headcount - but IT will find it hard to compete with SaaS companies offering CRM for £45 per seat and where those sales are being made direct to non-IT C level execs.
There is huge potential growth in cloud for enterprises to shift from old, creaking and often under-supported (because of the inevitable IT cuts) to modern, fully supported and managed SaaS services. This migration is only just starting. There are, of course, many barriers along the way (e.g. data privacy, data security etc) but this migration of apps to cloud looks pretty inevitable.