Worldwide IT spending is set to increase by 3.8% over the next year, reaching a total of $3.7 trillion, with the excitement surrounding big data driving much of that growth, according to the latest predictions from Gartner.

The latest news comes from Gartner’s IT Expo, taking place this week in Orlando. In a recorded keynote, Gartner’s Peter Sondergaard said that by 2015, big data would help to create around 4.4 million jobs worldwide, with 1.9 million of them being in the US. But big data’s tentacles will spread out much further than this, with each new big data role indirectly creating further employment opportunities for another three people, bringing a total of 6 million new jobs to the United States alone.

Sondergaard wasn’t drawn on how these new positions would be related to big data, or what the specific roles might be. Instead, he identified four key domains – big data, cloud, mobile and social computing – as the main drivers behind the world’s IT economy. Gartner has labeled these domains as a “Nexus of Forces” that will work in tandem to create more business and productivity synergy.

Mobile was identified as being particularly important. According to Sondergaard, mobile will be “the point of entry for all applications, delivering personalized, contextual experiences.”

Regarding enterprise, Sondergaard predicted that more than 50% of all enterprise applications will be running Android, iOS or Windows 8 by 2014, effectively rendering today’s architecture obsolete in just two years. To prepare for this, enterprises are being urged to consider what they will do in order to redevelop their infrastructure.

Sondergaard also spoke a little about the importance of cloud computing, which he said would act as “a foundation and carrier” for the other three domains. He said that most organizations are keen to do more than just trim operating costs by migrating to the cloud – they also want to benefit from new capabilities and approaches that they currently do not possess.