The recent launch of Google (s GOOG) and Microsoft (s MSFT) public clouds is looking well timed, as the corporate demand for public cloud services is about to go through a steep growth curve, research group, Gartner forecasts.

Gartner expects enterprise spending on public cloud services to grow from $91 billion worldwide in 2011 to $109 billion in 2012. By 2016, enterprise public cloud services spending will reach $207 billion.

“Business process as a service (BPaaS) still accounts for the vast majority of cloud spending by enterprises, but other areas such as platform as a service (PaaS), software as a service (SaaS) and infrastructure as a service (IaaS) are growing faster,” Richard Gordon, research vice president at Gartner.

Both companies have been very vocal in going after the enterprise customers. Amazon (s AMZN) chief technology officer Werner Vogels in a conversation at our Structure 2012 conference pointed out that Amazon, an early leader and pioneer in the cloud services is already in deep conversations with enterprises. Internet-based companies such as Dropbox have been the earliest and most aggressive adopters of cloud offerings.